Here's what I gather. There's so many phones out there (including the Galaxy S III) where a lot of owners complain about poor battery life. I hear a lot of people complain about how whatever stock battery is thrown in there is too low for practical usage. But then when you look at all the different varieties of extended capacity batteries out there, they always come packaged with proprietary back covers because the batteries themselves are often twice the thickness of the actual phone and won't fit otherwise. It appears to me, with insufficient technical knowledge of batteries or voltage, that higher capacity batteries require greater physical space to house whatever the inner workings are. And yet, phone manufacturers appear hell bent on making their phones as devoid of physical space as humanly possible. That being the case, despite all the high end processors and super HD screens, wireless radios, gps, and the whole nine yards, is it possible that the sheer thinness of smartphones nowadays are THE CAUSE of what's holding them back in the battery life department? I mean, at what point to we come to the limit as far as how much stuff one can cram into such a tiny case before we realize that a sufficient power source ALSO needs to go in there somewhere? And judging from these "extended" batteries, they apparently need a certain amount of room that these current phone designs simply do not allow. Do they seriously not think about this, or is that ALSO a part of their design, to deliberately gimp the phone to force you to buy extra batteries? Coming from a G2 and a Galaxy Player, the Galaxy S III is uncomfortably thin to where I feel like I need a case, not for protection, but just make it thick enough to hold in my hand and NOT worry about it slipping out of my hands. And I'm already an overly careful person with my electronics. How thin does a phone really NEED to be? Will we eventually have paper-thin phones in the future?