Slimness is absolutely part of the equation, since phones without the small grooves, nooks, and air pockets needed to make it so you can open a back cover and pull out a battery have the potential to be thinner.
In fact, when you don't have to design a product around popping out its battery, you have far more options. Engineers can use batteries in shapes, sizes, and configurations that deliver the requisite charge but are impractical to remove. That, in turn, can allow the industrial designer to create phones with creative contours.
Motorola certainly agrees. Manipulating the smartphone's shape and size was its great goal and accomplishment with the Droid Razr; its superskinny superphone measures less than 0.3 inch thick.
The Droid Razr Maxx delivers the second message that ultraslim phone bodies can play a practical role as well. At less than 0.4 inch thick, the sequel offers nearly double the battery capacity, at a thickness that's still slimmer than the 0.5-inch status quo.
