I am in the middle of creating some generic classes that can be reusable for lot of application.
For Eg: Share Functions - if we need this functionality in a projec
http://accu.org/index.php/journals/1594 offers detailed instructions.
OCHamcrest does it by taking a copy of the OS X version of the framework, and replacing its dynamic library with an iOS static library. (Xcode 4 version coming soon.)