The superefficient Biolite woodstove will boil water in minutes from twigs and charge your phone while it does it.
I first saw the $130 campstove demonstrated by Vinay Gupta, a permaculture/refugee tech guru whom we've featured here before. It uses an electric fan to drive combustion to unthinkable heights, allowing it to power a small thermoelectric generator that keeps the fan going (a small battery starts things off). The generator puts out enough power to run a USB charge-port that you can use to keep your phone and lights charged.
The whole thing is the size of a 1l nalgene water-bottle and weighs 2lbs, and runs on small twigs. It's rugged enough to take camping, and the company that makes it also donates units to developing world communities.
Mark wrote about the Biolite in 2012, and I kept my eye out for one ever since. As Pesco wrote, Biolite stations were used to keep phones charged after Sandy. The price has not come down in more than two years, which is kind of a shame, but having now seen the device in action, it's something I've come to seriously covet.