Today I received a few of the new Exolife rechargeable battery cases for the iPhone 4 by Exogear, currently they are still on pre-order. The case is very slim and the battery should double your iPhone's battery life. I'm currently charging the case so I did not test that yet. I'll be using the case for a few days before posting a review. Anyway you can check out the overview video of the whole thing. Right here. If you've got any questions, I'll try to answer them.