Biking For Mobile

I'm gonna be heading out for a long bike ride around town. Maybe even hop on the train and head out further. But as always, my main concern will be battery life for my G1.

I'm requesting help from anyone who might know of anyway to turn pedal-power to electricity for a small mobile device like a smartphone or mp3 player.

I came across this site, Convergence Tech, that offers similar to something what I'm looking at but in a smaller package if possible. Hopefully, it'll offer a USB or cigarette lighter input.

There are tons of information on the Internet for stationary bike generators. Some come prebuilt while there are DIY options.

For now, I think the easiest option is for me to carry around an external battery with a solar charger.

Note: I know its possible for bikes to generate power for a headlight. I suppose it's possible for that energy to be converted and stored in a portable battery unit.