The Freeplay Freecharge Weza is a portable rechargable 12v battery that can take 12v input from solar or wind power, 120/220v line power, or a unique foot pedal recharger producing up to 40w to juice up its lead-acid battery. When you need to use it you get 7Ah of power at 3v-12v, and enough amps to power jumper cables.
Street price is about $230-$240. Harness some of the power of small energetic boys to power your laptop? Go off the grid but keep your cell phone powered? Lots of possibilities, and more valuable the further away you go from line power.
I have seen plenty of ads for this one, but I've been looking for a review, and no reviews are yet to be found. It wasn't in stock for last year's gift-giving season.