I'm really new to IPhones as I've just got one couple days ago (IPhone 3G). I noticed that while on calls the battery seems to drain really fast and looking through the settings I see an Enable 3G option which is turned On by default. It says it drains battery life while on so I'm guessing this is the cause? Is it ok to turn this feature off? What exactly is the 3G option? I've been searching for it online and I can't really find a good detailed explanation. Also, does turning it off/on have any affect on the bill?