I really like Photojojo, and its new collection of photography projects and DIY ideas for cameras is definitely worth checking out, but I don't know that I feel the same about the Happy Helmet Camera Mount.
For $20 ($36 for two), you, or someone you'd like to make fun of, can strap a tripod mount through the vents of a helmet. Press record on your camera and start riding, skating, taking punches.
The only downside I can think of (other than the pointing and staring) is that compact cameras generally do a poor job of handling wind noise and I don't see it improving once one's strapped to your head. Helmet cams can run a couple hundred dollars though, and the video results likely won't be any better, making this an inexpensive alternative to the higher-priced gear.