GoPro Hero2. I paid $100 new at a local discount store a few weeks ago. Older model by today's standard - however a great deal for an unopened package.
Mounting on the body may yield shaky videos.
Using a dremel/rotary tool, I modifed and mounted one of the quick mounts on the rear wing of my nitro powered RC8.2 Buggy.
iDevice users:
RC8.2 Buggy with GoPro #1