diff --git a/lib/mongo_mapper.rb b/lib/mongo_mapper.rb
index 87753abd5..feab900b4 100644
--- a/lib/mongo_mapper.rb
+++ b/lib/mongo_mapper.rb
@@ -20,23 +20,28 @@ def initialize(document)
     end
   end
   
+  # @api public
   def self.connection
     @@connection ||= Mongo::Connection.new
   end
-
+  
+  # @api public
   def self.connection=(new_connection)
     @@connection = new_connection
   end
   
+  # @api public
   def self.logger
     connection.logger
   end
-
+  
+  # @api public
   def self.database=(name)
     @@database = nil
     @@database_name = name
   end
-
+  
+  # @api public
   def self.database
     if @@database_name.blank?
       raise 'You forgot to set the default database name: MongoMapper.database = "foobar"'
@@ -45,14 +50,17 @@ def self.database
     @@database ||= MongoMapper.connection.db(@@database_name)
   end
   
+  # @api private
   def self.ensured_indexes
     @@ensured_indexes ||= []
   end
   
+  # @api private
   def self.ensure_index(klass, keys, options={})
     ensured_indexes << {:klass => klass, :keys => keys, :options => options}
   end
   
+  # @api public
   def self.ensure_indexes!
     ensured_indexes.each do |index|
       unique = index[:options].delete(:unique)
@@ -60,6 +68,7 @@ def self.ensure_indexes!
     end
   end
   
+  # @api private
   module Finders
     def dynamic_find(finder, args)
       attributes = {}
@@ -83,6 +92,16 @@ def dynamic_find(finder, args)
       end
     end
   end
+  
+  # @api private
+  def self.use_time_zone?
+    Time.respond_to?(:zone) && Time.zone ? true : false
+  end
+  
+  # @api private
+  def self.time_class
+    use_time_zone? ? Time.zone : Time
+  end
 end
 
 require 'mongo_mapper/support'
diff --git a/lib/mongo_mapper/associations/belongs_to_polymorphic_proxy.rb b/lib/mongo_mapper/associations/belongs_to_polymorphic_proxy.rb
index 55ab0e972..94267886c 100644
--- a/lib/mongo_mapper/associations/belongs_to_polymorphic_proxy.rb
+++ b/lib/mongo_mapper/associations/belongs_to_polymorphic_proxy.rb
@@ -4,7 +4,7 @@ class BelongsToPolymorphicProxy < Proxy
       def replace(doc)
         if doc
           doc.save if doc.new?
-          id, type = doc.id, doc.class.name
+          id, type = doc._id, doc.class.name
         end
         
         @owner.send("#{@association.foreign_key}=", id)
diff --git a/lib/mongo_mapper/associations/belongs_to_proxy.rb b/lib/mongo_mapper/associations/belongs_to_proxy.rb
index dca435ec5..0a3cae161 100644
--- a/lib/mongo_mapper/associations/belongs_to_proxy.rb
+++ b/lib/mongo_mapper/associations/belongs_to_proxy.rb
@@ -4,7 +4,7 @@ class BelongsToProxy < Proxy
       def replace(doc)
         if doc
           doc.save if doc.new?
-          id = doc.id
+          id = doc._id
         end
 
         @owner.send("#{@association.foreign_key}=", id)
diff --git a/lib/mongo_mapper/associations/many_documents_as_proxy.rb b/lib/mongo_mapper/associations/many_documents_as_proxy.rb
index 19dd8ff4d..7f464e1af 100644
--- a/lib/mongo_mapper/associations/many_documents_as_proxy.rb
+++ b/lib/mongo_mapper/associations/many_documents_as_proxy.rb
@@ -3,13 +3,13 @@ module Associations
     class ManyDocumentsAsProxy < ManyDocumentsProxy
       protected
         def scoped_conditions
-          {as_type_name => @owner.class.name, as_id_name => @owner.id}
+          {as_type_name => @owner.class.name, as_id_name => @owner._id}
         end
 
         def apply_scope(doc)
           ensure_owner_saved
           doc.send("#{as_type_name}=", @owner.class.name)
-          doc.send("#{as_id_name}=", @owner.id)
+          doc.send("#{as_id_name}=", @owner._id)
           doc
         end
 
diff --git a/lib/mongo_mapper/associations/many_documents_proxy.rb b/lib/mongo_mapper/associations/many_documents_proxy.rb
index dbe13d37c..bdeb44c22 100644
--- a/lib/mongo_mapper/associations/many_documents_proxy.rb
+++ b/lib/mongo_mapper/associations/many_documents_proxy.rb
@@ -98,7 +98,7 @@ def method_missing(method, *args)
       
       protected
         def scoped_conditions
-          {self.foreign_key => @owner.id}
+          {self.foreign_key => @owner._id}
         end
         
         def scoped_options(options)
@@ -115,7 +115,7 @@ def ensure_owner_saved
 
         def apply_scope(doc)
           ensure_owner_saved
-          doc.send("#{self.foreign_key}=", @owner.id)
+          doc.send("#{self.foreign_key}=", @owner._id)
           doc
         end
 
diff --git a/lib/mongo_mapper/associations/many_embedded_proxy.rb b/lib/mongo_mapper/associations/many_embedded_proxy.rb
index 8e9cd5f39..6b90ff8ba 100644
--- a/lib/mongo_mapper/associations/many_embedded_proxy.rb
+++ b/lib/mongo_mapper/associations/many_embedded_proxy.rb
@@ -13,9 +13,10 @@ def build(attributes={})
         doc
       end
 
+      # TODO: test that both string and oid version work
       def find(id)
         load_target
-        @target.detect { |item| item.id == id }
+        @target.detect { |item| item.id == id || item._id == id }
       end
 
       def <<(*docs)
diff --git a/lib/mongo_mapper/document.rb b/lib/mongo_mapper/document.rb
index 531155f3a..5d3a3e50d 100644
--- a/lib/mongo_mapper/document.rb
+++ b/lib/mongo_mapper/document.rb
@@ -442,12 +442,12 @@ def save!
 
       def destroy
         return false if frozen?
-        self.class.delete(id) unless new?
+        self.class.delete(_id) unless new?
         freeze
       end
 
       def reload
-        self.class.find(id)
+        self.class.find(_id)
       end
 
     private
@@ -463,7 +463,7 @@ def create
 
       def assign_id
         if read_attribute(:_id).blank?
-          write_attribute(:_id, Mongo::ObjectID.new.to_s)
+          write_attribute :_id, Mongo::ObjectID.new
         end
       end
 
diff --git a/lib/mongo_mapper/embedded_document.rb b/lib/mongo_mapper/embedded_document.rb
index 6e4896ebe..7d6ee1e3e 100644
--- a/lib/mongo_mapper/embedded_document.rb
+++ b/lib/mongo_mapper/embedded_document.rb
@@ -16,7 +16,7 @@ def self.included(model)
 
         extend Validations::Macros
 
-        key :_id, String
+        key :_id, Mongo::ObjectID
         attr_accessor :_root_document
       end
     end
@@ -61,6 +61,11 @@ def key(*args)
         
         key
       end
+      
+      def object_id_key?(name)
+        key = keys[name.to_s]
+        key && key.type == Mongo::ObjectID
+      end
 
       def embeddable?
         !self.ancestors.include?(Document)
@@ -193,7 +198,7 @@ def initialize(attrs={})
 
         if self.class.embeddable? 
           if read_attribute(:_id).blank?
-            write_attribute :_id, Mongo::ObjectID.new.to_s
+            write_attribute :_id, Mongo::ObjectID.new
             @new_document = true
           else
             @new_document = false
@@ -275,15 +280,20 @@ def []=(name, value)
       end
 
       def ==(other)
-        other.is_a?(self.class) && id == other.id
+        other.is_a?(self.class) && _id == other._id
       end
 
       def id
-        read_attribute(:_id)
+        read_attribute(:_id).to_s
       end
 
       def id=(value)
         @using_custom_id = true
+        
+        if self.class.object_id_key?(:_id)
+          value = value.is_a?(String) ? Mongo::ObjectID.from_string(value) : value
+        end
+        
         write_attribute :_id, value
       end
 
diff --git a/lib/mongo_mapper/finder_options.rb b/lib/mongo_mapper/finder_options.rb
index 5a163b40d..f865278a2 100644
--- a/lib/mongo_mapper/finder_options.rb
+++ b/lib/mongo_mapper/finder_options.rb
@@ -8,17 +8,7 @@ module MongoMapper
   # useful for understanding how MongoMapper handles the parsing of finder 
   # conditions and options.
   #
-  # @private
-  class FinderOperator
-    def initialize(field, operator)
-      @field, @operator = field, operator
-    end
-    
-    def to_criteria(value)
-      {@field => {@operator => value}}
-    end
-  end
-  
+  # @private  
   class FinderOptions
     OptionKeys = [:fields, :select, :skip, :offset, :limit, :sort, :order]
 
@@ -72,10 +62,16 @@ def to_mongo_criteria(conditions, parent_key=nil)
 
         conditions.each_pair do |field, value|
           field = normalized_field(field)
+          
+          if @model.object_id_key?(field) && value.is_a?(String)
+            value = Mongo::ObjectID.from_string(value)
+          end
+          
           if field.is_a?(FinderOperator)
             criteria.merge!(field.to_criteria(value))
             next
           end
+          
           case value
             when Array
               operator_present = field.to_s =~ /^\$/
@@ -128,4 +124,14 @@ def to_mongo_sort_piece(str)
         [field, direction]
       end
   end
+  
+  class FinderOperator
+    def initialize(field, operator)
+      @field, @operator = field, operator
+    end
+    
+    def to_criteria(value)
+      {@field => {@operator => value}}
+    end
+  end
 end
diff --git a/lib/mongo_mapper/support.rb b/lib/mongo_mapper/support.rb
index e94125314..e0ed6aa6c 100644
--- a/lib/mongo_mapper/support.rb
+++ b/lib/mongo_mapper/support.rb
@@ -138,33 +138,21 @@ class Symbol
   end
 end
 
-class Time
+class Time  
   def self.to_mongo(value)
     if value.nil? || value == ''
       nil
     else
-      to_utc_time(value)
+      time = MongoMapper.time_class.parse(value.to_s)
+      time && time.utc
     end
   end
   
   def self.from_mongo(value)
-    if Time.respond_to?(:zone) && Time.zone && value.present?
+    if MongoMapper.use_time_zone? && value.present?
       value.in_time_zone(Time.zone)
     else
       value
     end
   end
-  
-  def self.to_utc_time(value)
-    to_local_time(value).try(:utc)
-  end
-  
-  # make sure we have a time and that it is local
-  def self.to_local_time(value)
-    if Time.respond_to?(:zone) && Time.zone
-      Time.zone.parse(value.to_s)
-    else
-      Time.parse(value.to_s)
-    end
-  end
 end
\ No newline at end of file
diff --git a/lib/mongo_mapper/validations.rb b/lib/mongo_mapper/validations.rb
index 2e9c38dc4..ab3459590 100644
--- a/lib/mongo_mapper/validations.rb
+++ b/lib/mongo_mapper/validations.rb
@@ -15,7 +15,7 @@ def valid?(instance)
         return true if allow_blank && value.blank?
         base_conditions = case_sensitive ? {self.attribute => value} : {}
         doc = instance.class.first(base_conditions.merge(scope_conditions(instance)).merge(where_conditions(instance)))
-        doc.nil? || instance.id == doc.id
+        doc.nil? || instance._id == doc._id
       end
 
       def message(instance)
diff --git a/test/functional/associations/test_belongs_to_polymorphic_proxy.rb b/test/functional/associations/test_belongs_to_polymorphic_proxy.rb
index c9d506fb7..181cf50d9 100644
--- a/test/functional/associations/test_belongs_to_polymorphic_proxy.rb
+++ b/test/functional/associations/test_belongs_to_polymorphic_proxy.rb
@@ -19,11 +19,11 @@ def setup
     status.target = project
     status.save.should be_true
 
-    from_db = Status.find(status.id)
-    from_db.target.nil?.should be_false
-    from_db.target_id.should == project.id
-    from_db.target_type.should == "Project"
-    from_db.target.name.should == "mongomapper"
+    status = status.reload
+    status.target.nil?.should be_false
+    status.target_id.should == project._id
+    status.target_type.should == "Project"
+    status.target.name.should == "mongomapper"
   end
 
   should "unset the association" do
@@ -32,11 +32,11 @@ def setup
     status.target = project
     status.save.should be_true
 
-    from_db = Status.find(status.id)
-    from_db.target = nil
-    from_db.target_type.nil?.should be_true
-    from_db.target_id.nil?.should be_true
-    from_db.target.nil?.should be_true
+    status = status.reload
+    status.target = nil
+    status.target_type.nil?.should be_true
+    status.target_id.nil?.should be_true
+    status.target.nil?.should be_true
   end
   
   context "association id set but document not found" do
diff --git a/test/functional/associations/test_belongs_to_proxy.rb b/test/functional/associations/test_belongs_to_proxy.rb
index 6db21d76e..b32794b77 100644
--- a/test/functional/associations/test_belongs_to_proxy.rb
+++ b/test/functional/associations/test_belongs_to_proxy.rb
@@ -42,6 +42,7 @@ def setup
   end
   
   should "return nil if id set but document not found" do
-    @comment_class.new(:name => 'Foo', :post_id => '1234').post.nil?.should be_true
+    id = Mongo::ObjectID.new
+    @comment_class.new(:name => 'Foo', :post_id => id).post.nil?.should be_true
   end
 end
\ No newline at end of file
diff --git a/test/functional/associations/test_many_documents_as_proxy.rb b/test/functional/associations/test_many_documents_as_proxy.rb
index bea083232..06edfb7cf 100644
--- a/test/functional/associations/test_many_documents_as_proxy.rb
+++ b/test/functional/associations/test_many_documents_as_proxy.rb
@@ -35,19 +35,19 @@ def setup
         PostComment.new(:body => 'baz')
       ]
     }.should change { PostComment.count }.by(3)
-
-    from_db = Post.find(post.id)
-    from_db.comments.size.should == 3
-    from_db.comments[0].body.should == 'foo'
-    from_db.comments[1].body.should == 'bar'
-    from_db.comments[2].body.should == 'baz'
+    
+    post = post.reload
+    post.comments.size.should == 3
+    post.comments[0].body.should == 'foo'
+    post.comments[1].body.should == 'bar'
+    post.comments[2].body.should == 'baz'
   end
 
   context "build" do
     should "assign foreign key" do
       post = Post.new
       comment = post.comments.build
-      comment.commentable_id.should == post.id
+      comment.commentable_id.should == post._id
     end
 
     should "assign _type" do
@@ -67,7 +67,7 @@ def setup
     should "assign foreign key" do
       post = Post.new
       comment = post.comments.create
-      comment.commentable_id.should == post.id
+      comment.commentable_id.should == post._id
     end
 
     should "assign _type" do
@@ -166,25 +166,25 @@ def setup
 
     context "with one id" do
       should "work for id in association" do
-        @post.comments.find(@comment2.id).should == @comment2
+        @post.comments.find(@comment2._id).should == @comment2
       end
 
       should "not work for id not in association" do
         lambda {
-          @post.comments.find!(@comment5.id)
+          @post.comments.find!(@comment5._id)
         }.should raise_error(MongoMapper::DocumentNotFound)
       end
     end
 
     context "with multiple ids" do
       should "work for ids in association" do
-        posts = @post.comments.find!(@comment1.id, @comment2.id)
+        posts = @post.comments.find!(@comment1._id, @comment2._id)
         posts.should == [@comment1, @comment2]
       end
 
       should "not work for ids not in association" do
         lambda {
-          @post.comments.find!(@comment1.id, @comment2.id, @comment4.id)
+          @post.comments.find!(@comment1._id, @comment2._id, @comment4._id)
         }.should raise_error(MongoMapper::DocumentNotFound)
       end
     end
diff --git a/test/functional/associations/test_many_embedded_polymorphic_proxy.rb b/test/functional/associations/test_many_embedded_polymorphic_proxy.rb
index 91d30311e..bb712d534 100644
--- a/test/functional/associations/test_many_embedded_polymorphic_proxy.rb
+++ b/test/functional/associations/test_many_embedded_polymorphic_proxy.rb
@@ -24,9 +24,9 @@ def setup
     catalog.medias = [Video.new("file" => "video.mpg", "length" => 3600)]
     catalog.save.should be_true
 
-    from_db = Catalog.find(catalog.id)
-    from_db.medias.size.should == 1
-    from_db.medias[0].file.should == "video.mpg"
+    catalog = catalog.reload
+    catalog.medias.size.should == 1
+    catalog.medias[0].file.should == "video.mpg"
   end
 
   should "store different associations" do      
@@ -38,15 +38,15 @@ def setup
     ]
     catalog.save.should be_true
     
-    from_db = Catalog.find(catalog.id)
-    from_db.medias.size.should == 3
-    from_db.medias[0].file.should == "video.mpg"
-    from_db.medias[0].length.should == 3600
-    from_db.medias[1].file.should == "music.mp3"
-    from_db.medias[1].bitrate.should == "128kbps"
-    from_db.medias[2].file.should == "image.png"
-    from_db.medias[2].width.should == 800
-    from_db.medias[2].height.should == 600
+    catalog = catalog.reload
+    catalog.medias.size.should == 3
+    catalog.medias[0].file.should == "video.mpg"
+    catalog.medias[0].length.should == 3600
+    catalog.medias[1].file.should == "music.mp3"
+    catalog.medias[1].bitrate.should == "128kbps"
+    catalog.medias[2].file.should == "image.png"
+    catalog.medias[2].width.should == 800
+    catalog.medias[2].height.should == 600
   end
   
   context "With modularized models" do
@@ -75,16 +75,16 @@ def setup
       fleet.transports[2].year.should == 2008      
       fleet.save.should be_true
       
-      from_db = TrModels::Fleet.find(fleet.id)
-      from_db.transports.size.should == 3
-      from_db.transports[0].license_plate.should == "GGG123"
-      from_db.transports[0].icu.should be_true
-      from_db.transports[1].license_plate.should == "ABC123"
-      from_db.transports[1].model.should == "VW Golf"
-      from_db.transports[1].year.should == 2001
-      from_db.transports[2].license_plate.should == "DEF123"
-      from_db.transports[2].model.should == "Honda Accord"
-      from_db.transports[2].year.should == 2008      
+      fleet = fleet.reload
+      fleet.transports.size.should == 3
+      fleet.transports[0].license_plate.should == "GGG123"
+      fleet.transports[0].icu.should be_true
+      fleet.transports[1].license_plate.should == "ABC123"
+      fleet.transports[1].model.should == "VW Golf"
+      fleet.transports[1].year.should == 2001
+      fleet.transports[2].license_plate.should == "DEF123"
+      fleet.transports[2].model.should == "Honda Accord"
+      fleet.transports[2].year.should == 2008      
     end
     
     should "default reader to empty array" do
@@ -104,9 +104,9 @@ def setup
       fleet.transports = [TrModels::Car.new("license_plate" => "DCU2013", "model" => "Honda Civic")]
       fleet.save.should be_true
     
-      from_db = TrModels::Fleet.find(fleet.id)
-      from_db.transports.size.should == 1
-      from_db.transports[0].license_plate.should == "DCU2013"
+      fleet = fleet.reload
+      fleet.transports.size.should == 1
+      fleet.transports[0].license_plate.should == "DCU2013"
     end
     
     should "store different associations" do
@@ -118,15 +118,15 @@ def setup
       ]
       fleet.save.should be_true
     
-      from_db = TrModels::Fleet.find(fleet.id)
-      from_db.transports.size.should == 3
-      from_db.transports[0].license_plate.should == "ABC1223"
-      from_db.transports[0].model.should == "Honda Civic"
-      from_db.transports[0].year.should == 2003
-      from_db.transports[1].license_plate.should == "XYZ9090"
-      from_db.transports[1].max_passengers.should == 51
-      from_db.transports[2].license_plate.should == "HDD3030"
-      from_db.transports[2].icu.should == true
+      fleet = fleet.reload
+      fleet.transports.size.should == 3
+      fleet.transports[0].license_plate.should == "ABC1223"
+      fleet.transports[0].model.should == "Honda Civic"
+      fleet.transports[0].year.should == 2003
+      fleet.transports[1].license_plate.should == "XYZ9090"
+      fleet.transports[1].max_passengers.should == 51
+      fleet.transports[2].license_plate.should == "HDD3030"
+      fleet.transports[2].icu.should == true
     end
   end
 
diff --git a/test/functional/associations/test_many_embedded_proxy.rb b/test/functional/associations/test_many_embedded_proxy.rb
index 35cf85696..0b23092e6 100644
--- a/test/functional/associations/test_many_embedded_proxy.rb
+++ b/test/functional/associations/test_many_embedded_proxy.rb
@@ -26,10 +26,10 @@ def setup
     project.addresses << chi
     project.save
 
-    from_db = Project.find(project.id)
-    from_db.addresses.size.should == 2
-    from_db.addresses[0].should == sb
-    from_db.addresses[1].should == chi
+    project = project.reload
+    project.addresses.size.should == 2
+    project.addresses[0].should == sb
+    project.addresses[1].should == chi
   end
   
   should "allow embedding arbitrarily deep" do
@@ -47,10 +47,10 @@ def setup
     doc = @document.new(:person => meg)
     doc.save
     
-    from_db = @document.find(doc.id)
-    from_db.person.name.should == 'Meg'
-    from_db.person.child.name.should == 'Steve'
-    from_db.person.child.child.name.should == 'Linda'
+    doc = doc.reload
+    doc.person.name.should == 'Meg'
+    doc.person.child.name.should == 'Steve'
+    doc.person.child.child.name.should == 'Linda'
   end
   
   should "allow assignment of 'many' embedded documents using a hash" do
@@ -70,12 +70,12 @@ def setup
     pet_lover.pets[1].species.should == "Siberian Husky"
     pet_lover.save.should be_true
     
-    from_db = RealPerson.find(pet_lover.id)
-    from_db.name.should == "Mr. Pet Lover"
-    from_db.pets[0].name.should == "Jimmy"
-    from_db.pets[0].species.should == "Cocker Spainel"
-    from_db.pets[1].name.should == "Sasha"
-    from_db.pets[1].species.should == "Siberian Husky"
+    pet_lover = pet_lover.reload
+    pet_lover.name.should == "Mr. Pet Lover"
+    pet_lover.pets[0].name.should == "Jimmy"
+    pet_lover.pets[0].species.should == "Cocker Spainel"
+    pet_lover.pets[1].name.should == "Sasha"
+    pet_lover.pets[1].species.should == "Siberian Husky"
   end
 
   context "embedding many embedded documents" do
@@ -101,13 +101,13 @@ def setup
       doc.people << meg
       doc.save
 
-      from_db = @document.find(doc.id)
-      from_db.people.first.name.should == "Meg"
-      from_db.people.first.pets.should_not == []
-      from_db.people.first.pets.first.name.should == "Sparky"
-      from_db.people.first.pets.first.species.should == "Dog"
-      from_db.people.first.pets[1].name.should == "Koda"
-      from_db.people.first.pets[1].species.should == "Dog"
+      doc = doc.reload
+      doc.people.first.name.should == "Meg"
+      doc.people.first.pets.should_not == []
+      doc.people.first.pets.first.name.should == "Sparky"
+      doc.people.first.pets.first.species.should == "Dog"
+      doc.people.first.pets[1].name.should == "Koda"
+      doc.people.first.pets[1].species.should == "Dog"
     end
 
     should "create a reference to the root document for all embedded documents before save" do
@@ -139,7 +139,7 @@ def setup
   should "allow finding by id" do
     sparky = Pet.new(:name => "Sparky", :species => "Dog")
     meg = Person.new(:name => "Meg", :pets => [sparky])
-    meg.pets.find(sparky.id).should == sparky
+    meg.pets.find(sparky._id).should == sparky
   end
   
   context "extending the association" do
diff --git a/test/functional/associations/test_many_polymorphic_proxy.rb b/test/functional/associations/test_many_polymorphic_proxy.rb
index 395c6a62a..c06690c86 100644
--- a/test/functional/associations/test_many_polymorphic_proxy.rb
+++ b/test/functional/associations/test_many_polymorphic_proxy.rb
@@ -34,8 +34,8 @@ def setup
       ]
     }.should change { Message.count }.by(3)
     
-    from_db = Room.find(room.id)
-    messages = from_db.messages.all :order => "position"
+    room = room.reload
+    messages = room.messages.all :order => "position"
     messages.size.should == 3
     messages[0].body.should == 'John entered room'
     messages[1].body.should == 'Heyyyoooo!'
@@ -48,8 +48,8 @@ def setup
     room.messages.push    Exit.new(:body => 'John entered the room', :position => 2)
     room.messages.concat  Chat.new(:body => 'Holla!'             , :position => 3)
     
-    from_db = Room.find(room.id)
-    messages = from_db.messages.all :order => "position"
+    room = room.reload
+    messages = room.messages.all :order => "position"
     messages[0]._type.should == 'Enter'
     messages[1]._type.should == 'Exit'
     messages[2]._type.should == 'Chat'
@@ -59,7 +59,7 @@ def setup
     should "assign foreign key" do
       room = Room.create
       message = room.messages.build
-      message.room_id.should == room.id
+      message.room_id.should == room._id
     end
     
     should "assign _type" do
@@ -79,7 +79,7 @@ def setup
     should "assign foreign key" do
       room = Room.create
       message = room.messages.create
-      message.room_id.should == room.id
+      message.room_id.should == room._id
     end
     
     should "assign _type" do
@@ -254,12 +254,12 @@ def setup
     
     context "with one id" do
       should "work for id in association" do
-        @lounge.messages.find(@lm2.id).should == @lm2
+        @lounge.messages.find(@lm2._id).should == @lm2
       end
       
       should "not work for id not in association" do
         lambda {
-          @lounge.messages.find!(@hm2.id)
+          @lounge.messages.find!(@hm2._id)
         }.should raise_error(MongoMapper::DocumentNotFound)
       end
     end
@@ -280,13 +280,13 @@ def setup
     
     context "with multiple ids" do
       should "work for ids in association" do
-        messages = @lounge.messages.find(@lm1.id, @lm2.id)
+        messages = @lounge.messages.find(@lm1._id, @lm2._id)
         messages.should == [@lm1, @lm2]
       end
       
       should "not work for ids not in association" do
         lambda {
-          @lounge.messages.find!(@lm1.id, @lm2.id, @hm2.id)
+          @lounge.messages.find!(@lm1._id, @lm2._id, @hm2._id)
         }.should raise_error(MongoMapper::DocumentNotFound)
       end
     end
diff --git a/test/functional/associations/test_many_proxy.rb b/test/functional/associations/test_many_proxy.rb
index 580a5d482..e2110c2cf 100644
--- a/test/functional/associations/test_many_proxy.rb
+++ b/test/functional/associations/test_many_proxy.rb
@@ -25,9 +25,9 @@ def setup
     project.statuses = [Status.new("name" => "ready")]
     project.save.should be_true
 
-    from_db = Project.find(project.id)
-    from_db.statuses.size.should == 1
-    from_db.statuses[0].name.should == "ready"
+    project = project.reload
+    project.statuses.size.should == 1
+    project.statuses[0].name.should == "ready"
   end
   
   should "correctly assign foreign key when using <<, push and concat" do
@@ -36,17 +36,17 @@ def setup
     project.statuses.push   Status.new(:name => 'push')
     project.statuses.concat Status.new(:name => 'concat')
     
-    from_db = Project.find(project.id)
-    from_db.statuses[0].project_id.should == project.id
-    from_db.statuses[1].project_id.should == project.id
-    from_db.statuses[2].project_id.should == project.id
+    project = project.reload
+    project.statuses[0].project_id.should == project._id
+    project.statuses[1].project_id.should == project._id
+    project.statuses[2].project_id.should == project._id
   end
   
   context "build" do
     should "assign foreign key" do
       project = Project.create
       status = project.statuses.build
-      status.project_id.should == project.id
+      status.project_id.should == project._id
     end
 
     should "allow assigning attributes" do
@@ -60,7 +60,7 @@ def setup
     should "assign foreign key" do
       project = Project.create
       status = project.statuses.create(:name => 'Foo!')
-      status.project_id.should == project.id
+      status.project_id.should == project._id
     end
     
     should "save record" do
@@ -81,7 +81,7 @@ def setup
     should "assign foreign key" do
       project = Project.create
       status = project.statuses.create!(:name => 'Foo!')
-      status.project_id.should == project.id
+      status.project_id.should == project._id
     end
     
     should "save record" do
@@ -105,7 +105,6 @@ def setup
     end
   end
   
-  
   context "count" do
     should "work scoped to association" do
       project = Project.create
@@ -316,25 +315,25 @@ def setup
     
     context "with one id" do
       should "work for id in association" do
-        @project1.statuses.find(@complete.id).should == @complete
+        @project1.statuses.find(@complete._id).should == @complete
       end
       
       should "not work for id not in association" do
         lambda {
-          @project1.statuses.find!(@archived.id)
+          @project1.statuses.find!(@archived._id)
         }.should raise_error(MongoMapper::DocumentNotFound)
       end
     end
     
     context "with multiple ids" do
       should "work for ids in association" do
-        statuses = @project1.statuses.find(@brand_new.id, @complete.id)
+        statuses = @project1.statuses.find(@brand_new._id, @complete._id)
         statuses.should == [@brand_new, @complete]
       end
       
       should "not work for ids not in association" do
         lambda {
-          @project1.statuses.find!(@brand_new.id, @complete.id, @archived.id)
+          @project1.statuses.find!(@brand_new._id, @complete._id, @archived._id)
         }.should raise_error(MongoMapper::DocumentNotFound)
       end
     end
diff --git a/test/functional/test_associations.rb b/test/functional/test_associations.rb
index 29ad8ee9c..e6c30ba0d 100644
--- a/test/functional/test_associations.rb
+++ b/test/functional/test_associations.rb
@@ -14,7 +14,7 @@ class AwesomeTag
       include MongoMapper::EmbeddedDocument
       
       key :name, String
-      key :post_id, String
+      key :post_id, Mongo::ObjectID
       
       belongs_to :post, :class_name => 'AssociationsTest::AwesomeUser'
     end
@@ -22,7 +22,7 @@ class AwesomeTag
     class AwesomePost
       include MongoMapper::Document
       
-      key :creator_id, String
+      key :creator_id, Mongo::ObjectID
       
       belongs_to :creator, :class_name => 'AssociationsTest::AwesomeUser'
       many :tags, :class_name => 'AssociationsTest::AwesomeTag', :foreign_key => :post_id
@@ -38,7 +38,7 @@ class AwesomePost
     post2 = AwesomePost.create(:creator => user, :tags => [tag2])
     user.posts.should == [post1, post2]
     
-    post1_from_db = AwesomePost.find(post1.id)
-    post1_from_db.tags.should == [tag1]
+    post1 = post1.reload
+    post1.tags.should == [tag1]
   end  
 end
\ No newline at end of file
diff --git a/test/functional/test_binary.rb b/test/functional/test_binary.rb
index b1b51742d..ce1451f7f 100644
--- a/test/functional/test_binary.rb
+++ b/test/functional/test_binary.rb
@@ -12,7 +12,7 @@ class BinaryTest < Test::Unit::TestCase
     doc = klass.new(:contents => '010101')
     doc.save
     
-    doc = klass.find(doc.id)
+    doc = doc.reload
     doc.contents.to_s.should == ByteBuffer.new('010101').to_s
   end
 end
\ No newline at end of file
diff --git a/test/functional/test_dirty.rb b/test/functional/test_dirty.rb
index 566ae273f..c66459c06 100644
--- a/test/functional/test_dirty.rb
+++ b/test/functional/test_dirty.rb
@@ -55,17 +55,17 @@ def setup
     should "not happen when loading from database" do
       doc = @document.create(:phrase => 'Foo')
       
-      from_db = @document.find(doc.id)
-      from_db.changed?.should be_false
+      doc = doc.reload
+      doc.changed?.should be_false
     end
     
     should "happen if changed after loading from database" do
       doc = @document.create(:phrase => 'Foo')
       
-      from_db = @document.find(doc.id)
-      from_db.changed?.should be_false
-      from_db.phrase = 'Bar'
-      from_db.changed?.should be_true
+      doc = doc.reload
+      doc.changed?.should be_false
+      doc.phrase = 'Bar'
+      doc.changed?.should be_true
     end
   end
   
diff --git a/test/functional/test_document.rb b/test/functional/test_document.rb
index 75efd8297..95685c4b4 100644
--- a/test/functional/test_document.rb
+++ b/test/functional/test_document.rb
@@ -37,7 +37,7 @@ def setup
 
   context "Loading a document from the database with keys that are not defined" do
     setup do
-      @id = Mongo::ObjectID.new.to_s
+      @id = Mongo::ObjectID.new
       @document.collection.insert({
         :_id            => @id,
         :first_name     => 'John',
@@ -80,7 +80,7 @@ def setup
         doc.tags = %w(foo bar)
         doc.save
         doc.tags.should == %w(foo bar)
-        @document.find(doc.id).tags.should == %w(foo bar)
+        doc.reload.tags.should == %w(foo bar)
       end
 
       should "work with assignment then <<" do
@@ -102,7 +102,7 @@ def setup
         doc.tags << "bar"
         doc.save
         doc.tags.should == %w(foo bar)
-        @document.find(doc.id).tags.should == %w(foo bar)
+        doc.reload.tags.should == %w(foo bar)
       end
     end
 
@@ -135,7 +135,7 @@ def setup
         doc.foo = {:baz => 'bar'}
         doc.save
 
-        doc = @document.find(doc.id)
+        doc = doc.reload
         doc.foo[:baz].should == 'bar'
         doc.foo['baz'].should == 'bar'
       end
@@ -156,12 +156,11 @@ def setup
         doc = @document.new
         doc.save
 
-        from_db = @document.find(doc.id)
-        from_db.window.should == WindowSize.new(600, 480)
+        doc = doc.reload
+        doc.window.should == WindowSize.new(600, 480)
       end
     end
 
-
     context "Creating a single document" do
       setup do
         @doc_instance = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
@@ -174,6 +173,8 @@ def setup
       should "automatically set id" do
         @doc_instance.id.should_not be_nil
         @doc_instance.id.size.should == 24
+        @doc_instance.id.should be_instance_of(String)
+        @doc_instance._id.should be_instance_of(Mongo::ObjectID)
       end
 
       should "no longer be new?" do
@@ -226,7 +227,7 @@ def setup
     context "Updating a document" do
       setup do
         doc = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
-        @doc_instance = @document.update(doc.id, {:age => 40})
+        @doc_instance = @document.update(doc._id, {:age => 40})
       end
 
       should "update attributes provided" do
@@ -246,8 +247,8 @@ def setup
     should "raise error when updating single doc if not provided id and attributes" do
       doc = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
       lambda { @document.update }.should raise_error(ArgumentError)
-      lambda { @document.update(doc.id) }.should raise_error(ArgumentError)
-      lambda { @document.update(doc.id, [1]) }.should raise_error(ArgumentError)
+      lambda { @document.update(doc._id) }.should raise_error(ArgumentError)
+      lambda { @document.update(doc._id, [1]) }.should raise_error(ArgumentError)
     end
 
     context "Updating multiple documents" do
@@ -256,8 +257,8 @@ def setup
         @doc2 = @document.create({:first_name => 'Steve', :last_name => 'Smith', :age => '28'})
 
         @doc_instances = @document.update({
-          @doc1.id => {:age => 30},
-          @doc2.id => {:age => 30},
+          @doc1._id => {:age => 30},
+          @doc2._id => {:age => 30},
         })
       end
 
@@ -272,8 +273,8 @@ def setup
       end
 
       should "update the documents" do
-        @document.find(@doc1.id).age.should == 30
-        @document.find(@doc2.id).age.should == 30
+        @document.find(@doc1._id).age.should == 30
+        @document.find(@doc2._id).age.should == 30
       end
     end
 
@@ -298,7 +299,7 @@ def setup
 
       context "with a single id" do
         should "work" do
-          @document.find(@doc1.id).should == @doc1
+          @document.find(@doc1._id).should == @doc1
         end
 
         should "return nil if document not found with find" do
@@ -314,15 +315,15 @@ def setup
 
       context "with multiple id's" do
         should "work as arguments" do
-          @document.find(@doc1.id, @doc2.id).should == [@doc1, @doc2]
+          @document.find(@doc1._id, @doc2._id).should == [@doc1, @doc2]
         end
 
         should "work as array" do
-          @document.find([@doc1.id, @doc2.id]).should == [@doc1, @doc2]
+          @document.find([@doc1._id, @doc2._id]).should == [@doc1, @doc2]
         end
 
         should "return array if array only has one element" do
-          @document.find([@doc1.id]).should == [@doc1]
+          @document.find([@doc1._id]).should == [@doc1]
         end
       end
 
@@ -442,8 +443,8 @@ def setup
       end
 
       should "be able to find by id" do
-        @document.find_by_id(@doc1.id).should == @doc1
-        @document.find_by_id(@doc2.id).should == @doc2
+        @document.find_by_id(@doc1._id).should == @doc1
+        @document.find_by_id(@doc2._id).should == @doc2
       end
 
       should "return nil if document not found" do
@@ -455,7 +456,7 @@ def setup
       setup do
         @doc1 = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
         @doc2 = @document.create({:first_name => 'Steve', :last_name => 'Smith', :age => '28'})
-        @document.delete(@doc1.id)
+        @document.delete(@doc1._id)
       end
 
       should "remove document from collection" do
@@ -463,7 +464,7 @@ def setup
       end
 
       should "not remove other documents" do
-        @document.find(@doc2.id).should_not be(nil)
+        @document.find(@doc2._id).should_not be(nil)
       end
     end
 
@@ -472,7 +473,7 @@ def setup
         @doc1 = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
         @doc2 = @document.create({:first_name => 'Steve', :last_name => 'Smith', :age => '28'})
         @doc3 = @document.create({:first_name => 'Steph', :last_name => 'Nunemaker', :age => '26'})
-        @document.delete(@doc1.id, @doc2.id)
+        @document.delete(@doc1._id, @doc2._id)
 
         @document.count.should == 1
       end
@@ -481,7 +482,7 @@ def setup
         @doc1 = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
         @doc2 = @document.create({:first_name => 'Steve', :last_name => 'Smith', :age => '28'})
         @doc3 = @document.create({:first_name => 'Steph', :last_name => 'Nunemaker', :age => '26'})
-        @document.delete([@doc1.id, @doc2.id])
+        @document.delete([@doc1._id, @doc2._id])
 
         @document.count.should == 1
       end
@@ -514,7 +515,7 @@ def setup
       setup do
         @doc1 = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
         @doc2 = @document.create({:first_name => 'Steve', :last_name => 'Smith', :age => '28'})
-        @document.destroy(@doc1.id)
+        @document.destroy(@doc1._id)
       end
 
       should "remove document from collection" do
@@ -522,7 +523,7 @@ def setup
       end
 
       should "not remove other documents" do
-        @document.find(@doc2.id).should_not be(nil)
+        @document.find(@doc2._id).should_not be(nil)
       end
     end
 
@@ -531,8 +532,8 @@ def setup
         @doc1 = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
         @doc2 = @document.create({:first_name => 'Steve', :last_name => 'Smith', :age => '28'})
         @doc3 = @document.create({:first_name => 'Steph', :last_name => 'Nunemaker', :age => '26'})
-        @document.destroy(@doc1.id, @doc2.id)
-
+        @document.destroy(@doc1._id, @doc2._id)
+        
         @document.count.should == 1
       end
 
@@ -540,7 +541,7 @@ def setup
         @doc1 = @document.create({:first_name => 'John', :last_name => 'Nunemaker', :age => '27'})
         @doc2 = @document.create({:first_name => 'Steve', :last_name => 'Smith', :age => '28'})
         @doc3 = @document.create({:first_name => 'Steph', :last_name => 'Nunemaker', :age => '26'})
-        @document.destroy([@doc1.id, @doc2.id])
+        @document.destroy([@doc1._id, @doc2._id])
 
         @document.count.should == 1
       end
@@ -594,7 +595,7 @@ class ::Thing
       context "many" do
         context "=> destroy" do
           setup do
-            Property.key :thing_id, String
+            Property.key :thing_id, Mongo::ObjectID
             Property.belongs_to :thing, :dependent => :destroy
             Thing.many :properties, :dependent => :destroy
 
@@ -617,7 +618,7 @@ class ::Thing
 
         context "=> delete_all" do
           setup do
-            Property.key :thing_id, String
+            Property.key :thing_id, Mongo::ObjectID
             Property.belongs_to :thing
             Thing.has_many :properties, :dependent => :delete_all
 
@@ -640,7 +641,7 @@ class ::Thing
 
         context "=> nullify" do
           setup do
-            Property.key :thing_id, String
+            Property.key :thing_id, Mongo::ObjectID
             Property.belongs_to :thing
             Thing.has_many :properties, :dependent => :nullify
 
@@ -665,7 +666,7 @@ class ::Thing
       context "belongs_to" do
         context "=> destroy" do
           setup do
-            Property.key :thing_id, String
+            Property.key :thing_id, Mongo::ObjectID
             Property.belongs_to :thing, :dependent => :destroy
             Thing.has_many :properties
 
@@ -785,25 +786,24 @@ class ::Thing
     end
 
     should "update attributes in the database" do
-      from_db = @document.find(@doc.id)
-      from_db.should == @doc
-      from_db.first_name.should == 'John'
-      from_db.age.should == 27
+      doc = @doc.reload
+      doc.should == @doc
+      doc.first_name.should == 'John'
+      doc.age.should == 27
     end
 
     should "allow to add custom attributes to the document" do
       @doc = @document.new(:first_name => 'David', :age => '26', :gender => 'male', :tags => [1, "2"])
       @doc.save
-      from_db = @document.find(@doc.id)
-      from_db.gender.should == 'male'
-      from_db.tags.should == [1, "2"]
+      doc = @doc.reload
+      doc.gender.should == 'male'
+      doc.tags.should == [1, "2"]
     end
 
     should "allow to use custom methods to assign properties" do
-      person = RealPerson.new(:realname => "David")
+      person = RealPerson.new(:realname => 'David')
       person.save
-      from_db = RealPerson.find(person.id)
-      from_db.name.should == "David"
+      person.reload.name.should == 'David'
     end
 
     context "with key of type date" do
@@ -833,17 +833,16 @@ class ::Thing
     end
 
     should "update attributes in the database" do
-      from_db = @document.find(@doc.id)
-      from_db.first_name.should == 'Johnny'
-      from_db.age.should == 30
+      doc = @doc.reload
+      doc.first_name.should == 'Johnny'
+      doc.age.should == 30
     end
 
     should "allow updating custom attributes" do
       @doc = @document.new(:first_name => 'David', :age => '26', :gender => 'male')
       @doc.gender = 'Male'
       @doc.save
-      from_db = @document.find(@doc.id)
-      from_db.gender.should == 'Male'
+      @doc.reload.gender.should == 'Male'
     end
   end
 
@@ -868,16 +867,15 @@ class ::Thing
     end
 
     should "update attributes in the database" do
-      from_db = @document.find(@doc.id)
-      from_db.should == @doc
-      from_db.first_name.should == 'Johnny'
-      from_db.age.should == 30
+      doc = @doc.reload
+      doc.should == @doc
+      doc.first_name.should == 'Johnny'
+      doc.age.should == 30
     end
 
     should "allow updating custom attributes" do
       @doc.update_attributes(:gender => 'mALe')
-      from_db = @document.find(@doc.id)
-      from_db.gender.should == 'mALe'
+      @doc.reload.gender.should == 'mALe'
     end
   end
 
@@ -897,9 +895,9 @@ class ::Thing
     end
 
     should "update attributes in the database" do
-      from_db = @document.find(@doc.id)
-      from_db.first_name.should == 'Johnny'
-      from_db.age.should == 30
+      doc = @doc.reload
+      doc.first_name.should == 'Johnny'
+      doc.age.should == 30
     end
   end
 
@@ -1031,14 +1029,14 @@ class ::DocGrandSon < ::DocSon; end
       steph = DocDaughter.create(:name => 'Steph')
 
       lambda {
-        DocSon.find!(steph.id)
+        DocSon.find!(steph._id)
       }.should raise_error(MongoMapper::DocumentNotFound)
     end
 
     should "not raise error for find with parent" do
       john = DocSon.create(:name => 'John')
 
-      DocParent.find!(john.id).should == john
+      DocParent.find!(john._id).should == john
     end
 
     should "count scoped to class" do
@@ -1073,7 +1071,7 @@ class ::DocGrandSon < ::DocSon; end
       steph = DocDaughter.create(:name => 'Steph')
 
       lambda {
-        DocSon.destroy(steph.id)
+        DocSon.destroy(steph._id)
       }.should raise_error(MongoMapper::DocumentNotFound)
     end
 
@@ -1082,7 +1080,7 @@ class ::DocGrandSon < ::DocSon; end
       steph = DocDaughter.create(:name => 'Steph')
 
       lambda {
-        DocSon.delete(steph.id)
+        DocSon.delete(steph._id)
       }.should_not change { DocParent.count }
     end
 
@@ -1142,9 +1140,9 @@ class ::DocGrandSon < ::DocSon; end
         @document.update(doc._id, { :first_name => 'Johnny' })
       end
 
-      from_db = @document.find(doc.id)
-      from_db.created_at.should == old_created_at
-      from_db.updated_at.should_not == old_updated_at
+      doc = doc.reload
+      doc.created_at.should == old_created_at
+      doc.updated_at.should_not == old_updated_at
     end
   end
 
@@ -1174,7 +1172,7 @@ class ::DocGrandSon < ::DocSon; end
   context "reload" do
     setup do
       @doc_instance_1 = @document.create({:first_name => 'Ryan', :last_name => 'Koopmans', :age => '37'})
-      @doc_instance_2 = @document.update(@doc_instance_1.id, {:age => '39'})
+      @doc_instance_2 = @document.update(@doc_instance_1._id, {:age => '39'})
     end
 
     should "load fresh information from the database" do
diff --git a/test/functional/test_embedded_document.rb b/test/functional/test_embedded_document.rb
index 980c4ab80..543fc44ed 100644
--- a/test/functional/test_embedded_document.rb
+++ b/test/functional/test_embedded_document.rb
@@ -28,9 +28,9 @@ def setup
       @doc.foo.city.should == 'South Bend'
       @doc.foo.state.should == 'IN'
 
-      from_db = @document.find(@doc.id)
-      from_db.foo.city.should == 'South Bend'
-      from_db.foo.state.should == 'IN'
+      doc = @doc.reload
+      doc.foo.city.should == 'South Bend'
+      doc.foo.state.should == 'IN'
     end
   end
   
@@ -58,8 +58,9 @@ def setup
       address = Address.new(:city => 'South Bend', :state => 'IN')
       doc = @document.new(:foo => address)
       doc.save
-      read_doc = @document.find(doc.id)
-      read_doc.foo.new?.should == false
+      
+      doc = doc.reload
+      doc.foo.new?.should == false
     end
   end
   
@@ -71,15 +72,16 @@ def setup
       person.pets << pet
       pet.save
 
-      doc = RealPerson.find(person.id)
-      doc.pets.first.should == pet
+      person = person.reload
+      person.pets.first.should == pet
     end
     
     should "save new keys" do
       person = RealPerson.new
       person[:new_attribute] = 'foobar'
       person.save
-      from_db = RealPerson.find(person.id)
+      
+      person = person.reload
       person.new_attribute.should == 'foobar'
     end
   end
@@ -92,14 +94,13 @@ def setup
       person.pets << pet
       pet.save
 
-      doc = RealPerson.find(person.id)
-      pet = doc.pets.first
+      person = person.reload
+      pet = person.pets.first
       pet.update_attributes :name => 'koda'
 
-      doc = RealPerson.find(person.id)
-      embedded = doc.pets.first
-      embedded.id.should == pet.id
-      embedded.name.should == 'koda'
+      person = person.reload
+      person.pets.first._id.should == pet._id
+      person.pets.first.name.should == 'koda'
     end
   end  
 end
diff --git a/test/functional/test_validations.rb b/test/functional/test_validations.rb
index 38e002257..62ad582ca 100644
--- a/test/functional/test_validations.rb
+++ b/test/functional/test_validations.rb
@@ -93,7 +93,7 @@ class ValidationsTest < Test::Unit::TestCase
     should "not update document" do
       @doc.name = nil
       @doc.save
-      @document.find(@doc.id).name.should == 'John Nunemaker'
+      @doc.reload.name.should == 'John Nunemaker'
     end
     
     should "populate document's errors" do
diff --git a/test/models.rb b/test/models.rb
index 586696459..6704a7330 100644
--- a/test/models.rb
+++ b/test/models.rb
@@ -40,7 +40,7 @@ class PostComment
   key :username, String, :default => 'Anonymous'
   key :body, String
 
-  key :commentable_id, String
+  key :commentable_id, Mongo::ObjectID
   key :commentable_type, String
   belongs_to :commentable, :polymorphic => true
 
@@ -62,7 +62,7 @@ class Message
   key :body, String
   key :position, Integer
   key :_type, String
-  key :room_id, String
+  key :room_id, Mongo::ObjectID
 
   belongs_to :room
 end
@@ -81,7 +81,7 @@ class Account
   include MongoMapper::Document
   
   key :_type, String
-  key :room_id, String
+  key :room_id, Mongo::ObjectID
   key :last_logged_in, Time
   
   belongs_to :room
@@ -145,7 +145,7 @@ def find_all_by_state(state)
 
 class Collaborator
   include MongoMapper::Document
-  key :project_id, String
+  key :project_id, Mongo::ObjectID
   key :name, String
   belongs_to :project
 end
@@ -153,8 +153,8 @@ class Collaborator
 class Status
   include MongoMapper::Document
 
-  key :project_id, String
-  key :target_id, String
+  key :project_id, Mongo::ObjectID
+  key :target_id, Mongo::ObjectID
   key :target_type, String
   key :name, String, :required => true
   key :position, Integer
@@ -166,7 +166,7 @@ class Status
 class RealPerson
   include MongoMapper::Document
 
-  key :room_id, String
+  key :room_id, Mongo::ObjectID
   key :name, String
   
   belongs_to :room
diff --git a/test/unit/test_embedded_document.rb b/test/unit/test_embedded_document.rb
index 19e64076e..7b75dc42e 100644
--- a/test/unit/test_embedded_document.rb
+++ b/test/unit/test_embedded_document.rb
@@ -292,6 +292,7 @@ class EmbeddedDocumentTest < Test::Unit::TestCase
     should "have to_param that is id" do
       doc = @document.new
       doc.to_param.should == doc.id
+      doc.to_param.should be_instance_of(String)
     end
     
     should "have access to class logger" do
diff --git a/test/unit/test_finder_options.rb b/test/unit/test_finder_options.rb
index 7813ce3fe..5ce0671fa 100644
--- a/test/unit/test_finder_options.rb
+++ b/test/unit/test_finder_options.rb
@@ -57,9 +57,28 @@ class FinderOptionsTest < Test::Unit::TestCase
     end
     
     should "convert id to _id" do
-      FinderOptions.new(Room, :id => '1').criteria.should == {
-        :_id => '1'
-      }
+      id = Mongo::ObjectID.new
+      FinderOptions.new(Room, :id => id).criteria.should == {:_id => id}
+    end
+    
+    should "make sure that _id's are object ids" do
+      id = Mongo::ObjectID.new
+      FinderOptions.new(Room, :_id => id.to_s).criteria.should == {:_id => id}
+    end
+    
+    should "work fine with _id's that are object ids" do
+      id = Mongo::ObjectID.new
+      FinderOptions.new(Room, :_id => id).criteria.should == {:_id => id}
+    end
+    
+    should "make sure other object id typed keys get converted" do
+      id = Mongo::ObjectID.new
+      FinderOptions.new(Message, :room_id => id.to_s).criteria.should == {:room_id => id}
+    end
+    
+    should "work fine with object ids for object id typed keys" do
+      id = Mongo::ObjectID.new
+      FinderOptions.new(Message, :room_id => id).criteria.should == {:room_id => id}
     end
     
     should "use $in for arrays" do
diff --git a/test/unit/test_mongomapper.rb b/test/unit/test_mongo_mapper.rb
similarity index 56%
rename from test/unit/test_mongomapper.rb
rename to test/unit/test_mongo_mapper.rb
index 04c9971ea..ae21a57d7 100644
--- a/test/unit/test_mongomapper.rb
+++ b/test/unit/test_mongo_mapper.rb
@@ -25,4 +25,28 @@ class MongoMapperTest < Test::Unit::TestCase
       MongoMapper::DocumentNotFound
     }.should_not raise_error
   end
+  
+  context "use_time_zone?" do
+    should "be true if Time.zone set" do
+      Time.zone = 'Hawaii'
+      MongoMapper.use_time_zone?.should be_true
+      Time.zone = nil
+    end
+    
+    should "be false if Time.zone not set" do
+      MongoMapper.use_time_zone?.should be_false
+    end
+  end
+  
+  context "time_class" do
+    should "be Time.zone if using time zones" do
+      Time.zone = 'Hawaii'
+      MongoMapper.time_class.should == Time.zone
+      Time.zone = nil
+    end
+    
+    should "be Time if not using time zones" do
+      MongoMapper.time_class.should == Time
+    end
+  end
 end