You can do some pretty interesting stuff with the Objective-C runtime. It's like Java introspection/reflection minus most of the headaches/penalties. For example, dynamically find the values for all ivars with a name that contains the substring 'style'.<p><a href="http://developer.apple.com/mac/library/documentation/Cocoa/Reference/ObjCRuntimeRef/Reference/reference.html" rel="nofollow">http://developer.apple.com/mac/library/documentation/Cocoa/R...</a>