The Voltaic backpack is a mobile power source, designed to charge your gadgets without tying you to a power outlet.

Embedded in the back of the bag are three tough, light weight, waterproof solar panels, which generate up to 4 watts of power. Inside the bag is a Li Ion battery pack. The battery pack can also be charged using the included AC travel charger or car charger. The backpack is powerful enough to charge most portable electronics (other than laptops) including: cell phones, cameras, two way radios, GPS's, PDA's, even iPods. Nice. Some interesting discussion on this here. Props to giantbicycle for the original post.