You may have the perfect adaptor to juice your smartphone or PDA through any kind of wall socket, but that becomes useless if you find yourself away from electricity all the time.

Maybe in situations like these, the $249 Voltaic Backpack is worth it. The solar-powered 4,400 mAh battery is already a novelty in itself, but what makes this geeky bag shine are the 11 bundled adapators. This means you can charge practically any gadget mobile or handheld at no additional cost. Laptops, since they need lots of juice, won't enjoy the mobile power.

The solar panels on the Voltaic Backpack come in Silver, Orange, Green, and Charcoal.