Canon S3 IS - Unofficial Firmware upgrade

[gmano]

CHDK is a firmware enhancement that operates on a number of Canon Cameras. CHDK gets loaded into your camera's memory upon bootup (either manually or automatically). It provides additional functionality beyond that currently provided by the native camera firmware.

CHDK is not a permanent firmware upgrade: you decide how it is loaded (manually or automatically) and you can always easily remove it.

A sampling of those additional features/functionality.
Main 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)
An "always on" Battery indicator
Additional features:

a depth-of-field (DOF)-calculator
File browser
Text reader
Calendar
Some fun tools and games
[edit]
Why would I want to use CHDK?
To get Raw file capability on cameras that don't have that ability
To get the ability to use scripts
to be able to know the battery status at all times (not just when it's about to run out of power)
you want or need any of the other enhancement features that CHDK provides

here is the link
CHDK in Brief - CHDK Wiki

 

[TechHead]

^Been posted before, I think. I've used it on the S2IS as well. GOod tool. RAW capability and the DOF calculator are invaluable.

 

[gmano]

^^ Sorry, I didnt know that its already posted here.