The GoPro Hero will take 1400 photos before the batteries die in the 2 or 5 second pic mode.
GoPro recommends that you use Energizer Lithiums for this type of device. A set of two AAA will last 1 hr of continuous video shooting according to their included instructions. You can also use NiMH rechargeable batteries- they are pricey, but will pay for themselves. With normal Energizer Lithiums, I generally will swap the battery set out per card. So fill the 2 gb card, and I'll swap. Likely there's still lots of juice left, but I'd hate for it to quit working in a particularly delicious set of curves.
Btw, here's the instructions that are included with the GoPro in pdf format:
http://www.pashnit.com/pics/products/gopro/operating_instructions.pdf
Here's another set, attempting to get some good shots of the newly installed Clearwater Lights. Still working up a little video shot along the bumpy road to Bodie SHP.
This timed pic sequence was shot with the GoPro attached to the 18" RAM arm, which is attached to a 1" ball mount off the bar end.
Goal was to get some shots of the lights.
But as you can see, if you like to fiddle with video of The Ride, this lil camera definitely allows a whole new world of funky angles and perspectives.