Well, I just received a new update The NEW Gopro 3 has been announced (1440p-HD). They claim 2x the resolution and 25% smaller and a host of more items that are really nice to have, good update. Bad news is the price is $399, but the good news is retailers are already discounting the Go Pro 2 (which is what I used) for $199. That is $100 bucks off!..
Anyway, To answer some questions. The battery will last about 2 hours of film time. You don't have to shoot every second of your ride. Some parts are just not worthy. The claim is that if you use a 32gig card, you will run out of battery before space. I found this to be true.
But, I purchased 3 extra battery's so that I can keep going. They are about $20 for the brand name and that is what you really want. I had a friend that went no name battery and it is junk and no longer works.
I guess I will purchase the Go pro 3 in spring and just lend out the old one to the rider behind me!