Let me start by saying that even I'm skeptical of the claim I'm making because it seems so improbable. However, I can't help but make this association because for the past week my battery life has been terrible and the only thing I've changed is that I put a case on my iPhone 4S. This is the case. For example, my battery life is at 23% with 3 hours and 30 minutes of usage and 7 hours of standby. I'm tweeting, messaging, instragramming, and browsing the web every so often. This is all on 3G, but it's basically what I do every day and have no problem getting a good 5.5 hours of usage out of. Then I usually make it home with around 30% and get on wifi. Tomorrow I'm going to take the case off for the day and see if I get different results. Anyone ever have a similar experience or can chime in?