Undefined C programs and Game Loops

If you're in the habit of using C (and who isn't), you'll want to read this. It's a fantastic description of all sorts of way you can write programs with undefined behaviours in C. It also goes over the horrible and unintuitive things that can happen when you do.
http://blog.regehr.org/archives/213

I've also been looking at tweaking the game loop inside space smilies and found an excellent article on how to write game loops. If you've ever want to write a game, read this first!
http://dev.koonsolo.com/7/dewitters-gameloop/