Moderator note: Please note that nearly all the posts on this thread are quite old, and that the original post was last updated 10 years ago. I'm sure that some of the links there are still good, but technology has changed quite a bit!
That being said, I notice we haven't had anything posted about charging batteries in the backcountry for the past couple of years. I try to avoid items with batteries as much as I can, but I know I'm way out of the mainstream these days!
Anyone want to start a new thread? Opportunity knocks!
EDIT,LATER: New thread, "Battery Charging for Backpackers" has been started below.