I saw this cam and thought it looked pretty cool for under 100 bucks. Comes with several mounting options. Made to strap to helmet but I can see it mounted on some boats, rhinos, towables etc. 2 GB SD card records 60 min of video at 640x480 and it's water resistant.
http://ak.buy.com/db_assets/prod_lrg.../203474227.jpg
Check out some of these videos I found on Youtube.
Mounted on a rocket
http://www.youtube.com/watch?v=-8JgHb0q7Bw
Mounted on a paint ball gun
http://www.youtube.com/watch?v=SuVts7xrBew
In car dash cam
http://www.youtube.com/watch?v=bjuRZ6F5x80
Hand held down a waterside
http://www.youtube.com/watch?v=cxI_PuUVYZQ
Review of cam
http://helmetcameracentral.com/2006/...helmet-camera/
On Buy.com for $92.99
http://www.buy.com/prod/helmet-video...203474227.html