[covati]

This is probably also based on user study data. I actually took part in a user study where we had to play with about 10 different phone and tablet sized lucite rectangles. They all had numbered grids and you had to hold it different ways and say how far up/down/over you could reach.

You also had to note your thoughts on holding, storing in pockets, etc.

Afterwards we had an open discussion period and most people seemed to agree that the iphone size was close to best, but that perhaps the screen should take up more of the real-estate, like how it does on the droid.