This one is definitely in the oldy-but-a-goody column, but our own Adam Christianson of MacCast stumbled on this tip for disabling quit and rewriting keyboard shortcuts for applications in OS X. Adam flipped out about how cool it was, and if he thinks it's cool, you'll think it's cool. It was originally written for Tiger, but Adam tested it out in Lion and Mountain Lion, and it still works. Note that this is a pretty geeky hack, and you'll need to use the terminal. Have fun!
Check It Out: Disabling Quit & Rewriting Keyboard Shortcuts