Bicycle-Powered GNU/Linux System
I must confess my initial scepticism to the One Laptop Per Child project has waned a little, not least because it does seem to have some genuinely cool technology behind it.
But I was nonetheless intrigued to find that there is already something similar that is not just on the drawing board, but off it and deep in the field (or jungle/savannah as the case may be). It's called the Inveneo Communication System. It uses GNU/Linux (of course), and draws as little as 12 Watts of power, which can be supplied by sun, wind or bicycle.