Demo-swizzling is a project mainly written in OBJECTIVE-C and C, it's free.
Basic demo of method swizzling. Prepared for Braindump 1 NYC, Jan 2011.
This code was prepared for BrainDump 1, Jan 17, 2011.
The corresponding slides can be found here: https://docs.google.com/present/view?id=d87qk88_2k4bzs8jh
Note that I've marked tags 1-5 to correspond with my stopping points in the presentation.