For what its worth, the Motorola Xoom will not charge from USB. Which is very irritating when you've just killed the charger.

FWIW, I find that the Apple AC/USB adapter for the iPad will charge anything I've thrown at it. Not so for 3rd-party imitations. Like the Xoom, Nook and, presumably, other high-powered devices, the iPad charger can put out more than the normal USB power (10W).

They are not too bad size/weight-wise. $29 from your local Apple store or on-line.

I also have the GoalZero Guide 10 battery recharger. Fully charged it will top-off my iPhone from 0 to 100 and have a bit left over. Can be recharged from a GoalZero folding solar panel or any USB port.

Yah, most any tablet is probably going to draw more than the standard USB 2.0 spec. allows.

Mark has a good point that something that is designed to charge one of these high powered devices is more likely to be able to charge other high power devices.

-john