Didn't know about this myself until I glanced through this month's PC Pro Mag...

CHDK - CHDK Wiki (http://chdk.wikia.com/wiki/CHDK)

Looks very cool indeed if you've got a supported PowerShot - giving a standard point'n'shoot the features of a pro-sumer (and more) - and best of all doesn't do anything at all to the original camera firmware!

Some features:

* Save images in RAW format
* Ability to run "Scripts" to automate the camera
* Live histogram (RGB, blended, luminance and for each RGB channel)
* Zebra mode (blinking highlights and shadows to show over/under exposed areas)
* An "always on" full range Battery indicator
* Ability to turn off automatic dark-frame subtraction
* a higher compression movie mode, and double the maximum video file size
* exposure times as long as 65 seconds
* exposure times as little as 1/10,000 of a second (though the latest version appears to go much higher even than this!)
* ability to use the USB port for a remote trigger input

Just waiting for G9 support now...............