I've just got a brand new iPhone 5 (my first), after years and years using a crappy Motorola RAZR - I am thoroughly enjoying it, of course, and haven't encountered any problems so far. Battery life seems in line with Apple's estimates, although I am still testing it. So my question is: WHAT is the biggest battery drainer in the iPhone 5? My impression so far is that the biggest drainer would be Location Services, followed perhaps by the 3G cellular option. I can only get some three or four days of standby/light usage when these options are used. What is your opinion on this? Any additional tips?