Over at Woot.com, they have a Two for Tuesday Energizer Energi To Go iPod/iPhone Battery Charger for $14.99. You're able to order up to three 2-packs. $5 shipping whether you buy 1 or 3. Good to use rechargable batteries with this so you dont throw away money on AA's and kill the enviroment, but it includes a 4-pack of engizer lithium batteries which are like $8.00. Note that this is one day only and expires at midnight central time and may sell out.
If you want to get an actual rechargeable battery pack and don't mind forking out the cash, the Mophie is supposed to be phenomenal- http://www.mophie.com/products/juice-pack-iphone-3g I was pretty close to biting on that Woot last night though. I'm really curious how much of a charge you get off of two AA's.
It says two charges for a set of alkalines, three for lithiums. I'm thinking a good full charge and an emergency charge with some rechargables. But the best thing about this Woot compared to the morphie is that you get to keep one and give one to your buddy.
2-3 charges sounds really high to me. But, with the price of those lithium batteries, the chargers are almost free when you look at the package deal.
