I didn't read every post here, so pardon if this was mentioned before...

My suggestion is to let you roam about the map with the keyboard or perhaps moving the mouse to the edge of the screen.. The dragging to get to the opposite side of the island gets monotonous. Also, this would help when your tryign to keep an eye on what a villager is doing (ie. selected) and still be able to scroll around the screen to check on the others or spot those elusive mushrooms.

I love the screensaver idea though. That would be pretty awesome.

Note: Wanted to mention that I am a windows user, not a palm or mac user.