Hello, just to let you know I did some changes to enable userless access, feel free to ignore

.gitignore

@@ -0,0 +1,2 @@
+*.swp
+*.swo

lib/foursquare_checkins.rb

@@ -37,4 +37,4 @@ def deletecomment(checkin_id, params={})
       perform_graph_request("checkins/#{checkin_id}/deletecomment", params, "post")
     end
   end
-end
+end

lib/foursquare_node.rb

@@ -1,22 +1,48 @@
+module MetaFour
+
+  BASE_URL = "https://api.foursquare.com:443/v2/"
+
+  attr_accessor :client_id, :client_secret
+
+  def base_url
+    @base_url || BASE_URL
+  end
+
+  def base_url=(value)
+    @base_url = value if value   
+  end
+end
+
 module Foursquare
+
   class Node
+    extend MetaFour
+
     def initialize(access_token)
-      @access_token       = access_token
-      @base_url = "https://api.foursquare.com:443/v2/"
+      @access_token = access_token
     end
 
-    def perform_graph_request(endpoint, params={}, method="get")
+    def self.perform_graph_request(endpoint, params={}, method="get")
       require 'net/http'
 
-      @query_string = "?"
-      @query_string += "oauth_token=#{CGI.escape(@access_token)}" unless @access_token.empty?
+      query_string = "?"
+      if params[:oauth_token]
+        query_string += "oauth_token=#{params[:oauth_token]}"
+      elsif params[:client_id] && params[:client_secret]
+        query_string += "client_id=#{params[:client_id]}&client_secret=#{params[:client_secret]}"
+      elsif @client_id && @client_secret
+        query_string += "client_id=#{@client_id}&client_secret=#{@client_secret}"
+      else
+        raise "client_id and client_secret or oauth_token are required."
+      end
+      params.reject! {|k,v| [:oauth_token, :client_secret, :client_id].include?(k) }
 
       if method=="get"
-        params.each{|key, val| @query_string += "&#{key}=#{val}"}
-        url = URI.parse("#{@base_url}#{endpoint}#{@query_string}")
+        params.each{|key, val| query_string += "&#{key}=#{val}"}
+        url = URI.parse("#{base_url}#{endpoint}#{query_string}")
         request = Net::HTTP::Get.new("#{url.path}?#{url.query}",{"Content-Type"=>"text/json"})
       else
-        url = URI.parse("#{@base_url}#{endpoint}#{@query_string}")
+        url = URI.parse("#{base_url}#{endpoint}#{query_string}")
         request = Net::HTTP::Post.new("#{url.path}?#{url.query}",{"Content-Type"=>"text/json"})
         request.set_form_data(params)
       end
@@ -26,8 +52,13 @@ def perform_graph_request(endpoint, params={}, method="get")
       response = JSON.parse(http.start {|http| http.request(request)}.body)
       response
     end
+
+    def perform_graph_request(endpoint, params={}, method="get")
+      h = {:oauth_token => @oauth_token}
+      self.class.perform_graph_request(endpoint, params.merge(h), method)
+    end
   end
-  
+
   def self.exchange_access_token(code, client_id, client_secret, callback)
     require 'net/http'
 

lib/foursquare_settings.rb

@@ -13,4 +13,4 @@ def set(setting_id, params={})
       perform_graph_request("settings/#{setting_id}/set", params, "post")
     end
   end
-end
+end

lib/foursquare_tips.rb

@@ -32,4 +32,4 @@ def unmark(tip_id)
       perform_graph_request("tips/#{tip_id}/unmark", {}, "post")
     end
   end
-end
+end

lib/foursquare_user.rb

@@ -13,12 +13,12 @@ def search(params={})
     end
 
     def requests
-      perform_graph_request("users/requests")
+      perform_graph_request("users/requests", {})
     end
 
     #Aspects
     def badges(user_id)
-      perform_graph_request("users/#{user_id}/badges")
+      perform_graph_request("users/#{user_id}/badges", {})
     end
 
     def checkins(user_id="self", params={})
@@ -31,7 +31,7 @@ def checkins(user_id="self", params={})
     end
 
     def friends(user_id="self")
-      perform_graph_request("users/#{user_id}/friends")
+      perform_graph_request("users/#{user_id}/friends", params)
     end
 
     def tips(user_id="self", params={})
@@ -49,7 +49,7 @@ def todos(user_id="self", params={})
     end
 
     def venuehistory(user_id="self")
-      perform_graph_request("users/#{user_id}/venuehistory")
+      perform_graph_request("users/#{user_id}/venuehistory", params)
     end
 
     #Actions
@@ -75,4 +75,4 @@ def setpings(user_id, params={})
       perform_graph_request("users/#{user_id}/setpings", params, "post")
     end
   end
-end
+end

lib/foursquare_venue.rb

@@ -15,30 +15,37 @@ def add(params={})
       perform_graph_request("venues/add", params, "post")
     end
 
-    def categories
-      perform_graph_request("venues/categories", {})
+    def self.categories(params={})
+      perform_graph_request("venues/categories", params)
     end
 
-    def search(params={})
+    def categories(params={})
+      perform_graph_request("venues/categories", params)
+    end
+
+    def self.search(params={})
       params = {:ll => "37.792694,-122.409325",
                 :llAcc => "100",
                 :alt => "0",
                 :altAcc=>"100",
                 :query=>"",
                 :limit=>"50",
                 :intent=>"checkin"}.merge!(params)
-
       perform_graph_request("venues/search", params)
     end
 
+    def search(params={})
+      self.class.search(params.merge(:oauth_token => @access_token))
+    end
+
     #Aspects
     def herenow(venue_id)
       perform_graph_request("venues/#{venue_id}/herenow", {})
     end
 
     #sort = recent or popular
     def tips(venue_id, params={:sort => "recent"})
-      perform_graph_request("venues/#{venue_id}/tips", {})
+      perform_graph_request("venues/#{venue_id}/tips", params)
     end
 
     #marktodo
@@ -68,4 +75,4 @@ def proposeedit(venue_id, params={})
       perform_graph_request("venues/#{venue_id}/proposeedit", params, "post")
     end
   end
-end
+end