using rspec's let feature to great effect.

Two changes here: the first is to use an awesome feature of rspec: let.

Basically, we can let rspec instantiate our object, which gets
all of that typing of long class names out of the way. It also lets
our tests focus on what's important, and ignore what isn't. Read the tests
now: "When the ip is this, I expect the locator to do that."

The second thing was breaking the last test into two. I wanted to do
this as a separate step, but it didn't work until I made the change:
you really had two assertions in that last one. It deserves its own
test.

spec/geolocator_spec.rb

@@ -2,6 +2,7 @@
 require 'geolocator'
 
 describe Geolocator do
+  let(:locator) { Geolocator.new(@ip) }
 
   describe "#ip_lookup" do    
     it "throws an ArgumentError error if no parameters passed" do
@@ -13,32 +14,43 @@
     end
 
     it "only accepts input that passes a basic IP regex" do
-      expect {Geolocator.new("sdfsadfsdf").ip_lookup}.to raise_error(RuntimeError,"Not a valid IPv4 address")
+      @ip = "sdfsadfsdf"
+      expect {locator.ip_lookup}.to raise_error(RuntimeError,"Not a valid IPv4 address")
     end
 
     it "should not accept localhost/loopback address" do
-      expect {Geolocator.new("127.0.0.1").ip_lookup}.to raise_error(RuntimeError,"Can't lookup localhost address. Please use an external IP address!")
+      @ip = "127.0.0.1"
+      expect {locator.ip_lookup}.to raise_error(RuntimeError,"Can't lookup localhost address. Please use an external IP address!")
     end
   end
 end
 
 describe Geolocator::FreeGeoIp do  
+  let(:geo_ip) { Geolocator::FreeGeoIp.new(@ip) }
   describe "#geolocate_ip" do
     it "successfully makes a HTTP request" do
-      expect{Geolocator::FreeGeoIp.new("231.4.8.6").geolocate_ip.success?}.to be_true
+      @ip = "231.4.8.6"
+      expect{geo_ip.geolocate_ip.success?}.to be_true
     end
 
     it "throws an error for HTTP statuses other than 200" do
-      expect {Geolocator::FreeGeoIp.new("0.0.0.0").geolocate_ip}.to raise_error(RuntimeError,"IP address not found")
+      @ip = "0.0.0.0"
+      expect {geo_ip.geolocate_ip}.to raise_error(RuntimeError,"IP address not found")
     end
 
     it "parses the HTTP body with JSON" do
-      Geolocator::FreeGeoIp.new("123.45.6.28").geolocate_ip.should be_an_instance_of Hash
+      @ip = "123.45.6.28"
+      geo_ip.geolocate_ip.should be_an_instance_of Hash
     end
 
     it "has a value for city" do
-      @result = Geolocator::FreeGeoIp.new("123.45.6.28").geolocate_ip["city"].should_not be_empty
-      expect {Geolocator::FreeGeoIp.new("240.0.0.0").geolocate_ip}.to raise_error(RuntimeError,"Incomplete record. Please try another address")
+      @ip = "123.45.6.28"
+      geo_ip.geolocate_ip["city"].should_not be_empty
+    end
+
+    it "raises a RuntimeError if there isn't a city" do
+      @ip = "240.0.0.0"
+      expect {geo_ip.geolocate_ip}.to raise_error(RuntimeError,"Incomplete record. Please try another address")
     end
   end      
 end