CHDK or the Canon Hacker's Development Kit is an ultimate firmware add-on for many Canon digital cameras. It turns your simple point-and-shoot camera into a powerhouse. It lets you control advanced settings, record time lapse videos, run scripts and many other impressive features. And best of all, CHDK doesn't destroy your camera's existing firmware.
To load CHDK, all you have to do is copy the CHDK program image onto the media card (usually an SD card) and insert it in your Canon camera and start it up. The camera will automatically detect and load the new program. To stop using CHDK, all you have to do is delete the file from the SD card.
Lifehacker carried an excellent article on supercharging your Canon point-and-shoot using CHDK. Here's another article on HackADay. I recommend you try it out!
