Hey Guys so I will make this as quick as possible, Over the last week I have been doing a bit of an experiment. Since I got the iPhone 4S back in October, I have always had a Plastic back case on the device. It was a generic case off of Amazon and I think I payed like $0.99 or something like that. While using the phone with the case, I noticed that even with marginal usage such as: Checking my email, sending Text messages, Facebook and twitter and some light web surfing, my phone would be come increasingly hot, sometimes to the point where it would be too hot to hold for a long period of time. That got me thinking, and I know that the batteries perform optimally under a certain temperature range, and all that excess heat could potentially mess with the battery and cause it to become shorter. So on with the experiment. Last week I believe it was Monday,I received a iPhone bumper in the mail and decided I would like to try out the bumper, after putting on the bumper and doing the light usage I mentioned before, I noticed two things, One the phone wasn't nearly as hot and two, the battery didn't drain nearly as much. So I decided I would use the bumper for the following week (this was last monday) to see if my results held true. A week and three days later and the results have been pretty unanimous... I have seen a increase in battery life, I currently am running at 41% battery life with 6 hours of usage and 23 hours and 59 minutes of standby. The iPhone has not been plugged in since the full charge and I have played words with friends done some intense internet browsing, streamed a couple of videos from YouTube, sent and received about 200 texts messages and did about an hour worth of talking on the phone. I'm curious to see what my fellow MacRumorian's have to say about this!