Kensington Mini Battery Extender and Charger Review
I've had the Kensington Mini Battery Extender and Charger since the first week I had my iPhone 3G and it's become a very handy accessory for me. There are many ways to save battery life on the iPhone 3G and first generation iPhone, but lets face it: eventually, you will have a day where you've used all of your iPhone's juice and you'll have no way to plug it in to recharge. Apple's design doesn't allow for a user replaceable battery, so until they design an iPhone with one, this is probably one of your best bets.
