CHDK is pretty awesome. I have it on my SD600 so I can shoot RAW. (DNG actually, as the original CRW format is not as well supported)
Thank you for the compliment! I love having a decent camera with me at all times via my phone. I also shoot a Canon T1i, but with a battery grip and EF 28-135mm IS lens it is a fairly big item to be carrying around everywhere. I'm hoping my SD600 will help bridge that gap and I'd say it has. Check out the thread I started here for a pic I got with it:
http://www.tfproject.org/tfp/tilted-...-greatest.html