Ran across this on another forum. I have not tried it myself as I have an S70, but it seems like most people are getting good results from what I've read.

http://lifehacker.com/387380/turn-your-poi...-a-super+camera

Here's a list of supported cameras and other features this enables

http://chdk.wikia.com/wiki/FAQ#Q._What_cam...CHDK_program.3F

Looks very interesting. Alas, my only Canon is a G9. Wish I had something around to try it out on.

--Marc