HyperMac, our favorite brand of precious-extra-juice-giving external batteries, has updated their line to offer 10W USB charging of the iPad. The four capacities will give your tablet a total run time ranging from 34 to 99 hours. Yes, that'll do.
If you were stuck on a steamboat with just your iPad and the beefy, 222Wh HyperMac, you'd be able to catch up on Lost—as in, watching every episode from the pilot up through the current one—without ever plugging into an outlet. What a reassuring thought.