After retaining the services of some kind of sorcerer I have figured out how to get Thrift to work with the iPhone/iPad (or at least get it to compile okay).
First, you want to grab the objective-c files with this command instead of from the wiki:
svn co http://svn.apache.org/repos/asf/incubator/thrift/trunk/lib/cocoa/src/ thrift-cocoa
Then, make a new Xcode project by going to New Project, selecting Framework & Library and Cocoa Framework. Click create and save it somewhere nice. Right click on Targets and select Add -> New Target. Choose Cocoa Touch and then Static Library. Give it a nice name. Go to the target's Build tab in info and change the Base SDK to iPhone Device (I'm using 3.2 but you can use whatever) and change Architectures to either Standard (armv6 armv7) or Optimized (armv7). Under the General tab add the Foundation and Cocoa frameworks.
Drag all of the files and folders you got from the svn repository into the Classes folder in the project. Check the copy items box and check the boxes next to both targets. Remove TSocketServer.h and .m from the Static Library's Copy Headers and Compile Sources folders respectively. You can now build the Static Library (and Framework optionally).
Open the project you want to use Thrift in and go to your target's General tab in info. Add the Static Library you just created to the Linked Libraries list. It should be named libYOUR_TARGET_NAME.a. Under the build tab go to Header Search Paths and add the path to the Thrift project you just created and check the recursive box.
Finally you just need to change the import statements in the Thrift generated code by simply removing the brackets and replacing them with quotes. You can now build you iPhone project again.