I followed the instructions in this article to create a static library:
http://developer.apple.com/library/ios/#technotes/iOSStaticLibraries/Articles/creating.html
I built it for iPhone simulator target. It built successfully, then I imported into a new project where I wanted to use it. It imported fine and there are no problems, but the library doesn't work. There are no library methods that I'm calling; rather the purpose of the library is to swizzle the UIViewController viewDidAppear method so that a piece of code gets executed every time a UIViewController appears. This piece of code is not getting called, despite my library being included in the "Link Binary With Libraries" build phase.
I know the problem isn't with the code itself because if I import the raw .m and .h source files not as a library, everything works fine.