This has nothing to do with Canon or CHDK, but I thought some here might be interested.
For the last few months a very small video/still camera has been available on Ebay from numerous Hong Kong sellers for about US$16, or less, with free shipping. It's usually referred to with some combination of 808, Key Chain camera, Key Chain DVR, or 808 spy camera. Well, it looks like one of those car security fobs, complete with fake buttons. In addition to the camera, you would also need a microSD card that's not included at that price. It's believed these are made from obsolete cellphone camera parts.
In recent models, this camera will shoot 720x480P video (MJPEG) at 30 fps, with audio (22K PCM), for up to about 50 minutes (with a 4GB SD card) on one battery charge. The quality of the video and audio, for the money, is quite remarkable. I don't know how much demand there is for spy cameras, but this has been a huge hit with the R/C airplane guys, and you can see examples of their flight videos on Youtube and Vimeo - search for 808 Keychain, or something similar. With the keychain detached, the camera weighs about 10 grams, which is why they like it so much. Well, and because at the price it doesn't matter much if it gets trashed when the plane crashes.
So, the authoritative website on this (a must-read before buying) is:http://www.chucklohr.com/808/
It appears that buying one of these is somewhat of a crapshoot as to exactly what model you'll get and whether it will work for long, or at all. But the one thing all the R/C people hate about it is the bright yellow date/time stamp that appears on all the videos - this apparently derives from the camera's spy heritage. :-)
One guy (Philippe) has hacked his "gumpack" camera, which is very similar to the keychain cameras, so as to change the font characters used in the date/time stamp so they are transparent. The way he was able to do this reads like a mystery novel:http://www.pluc.fr/2010/02/tear-down-and-hacking-around-gumpack-camera/
Well this is all a lot of fun for very little money. If any of the CHDK wizzards would like to participate in the date/time stamp removal, or other hacks, I'm sure Chuck, Philippe and the guys would appreciate it. Or, you know, you could just buy a couple of these and play with them.