Since I only have experience with one camera, I can't be relied upon to know the
bestcamera, but I have this one:

I've mounted it a bunch of different ways, including pointed backwards. It can take a
picture every 5 seconds for two hours, or it can take 45 minutes worth of video with audio.
Stores
jpgs and
avis on a 2 gig (max) sd card.
There's a newer model now, so it probably has better specs...
I took this video yesterday, don't judge the camera's picture quality by youtube's
compressed flashified version:
My camera is three megapixels, the newer one is five.

You can find the cameras a lot of places, on Amazon search for "gopro camera"...
-Mike