Marco Arment looks at different ways to charge an iPhone without AC power. Handy in the wake of Hurricane Sandy. He concludes:
I’d rather have the Tekkeon AA box and 40 lithium AAs, which could power my iPhone for about a month of frequent use. If I actually lose power for an entire month and burn through them all, presumably I will have spent part of that month finding some way to get a few extra AA batteries. And if that’s not possible, I probably have much bigger problems.
This is gong into my plans for an emergency/zombie attack kit.