I mentioned this somewhere else in this thread, but before touchpads, most laptops had either a nub (like the kind that Thinkpads still have today) or no mouse at all, and the keyboard was almost always on the lower edge. It really was great for typing.

http://oldcomputers.net/pics/ibm-thinkpad-750c.jpg

I wonder how feasible it would be to gut one of these things and update its internals (big fat battery and a small ARM SBC, maybe).