If the image size for the wallpapers has to be 1024X1024 because of the cropping that would mean that the object content(person, car, animal, etc..) should be in 128 pixels from each edge. Now what else has to be taken into account is how much space the dock takes up. Does anyone have any idea on how many more pixels from the edge will need to be padded to compensate for the dock in landscape and portrait modes?