Well, Steve Jobs just dropped a little nugget of history on us during his chat with Walt Mossberg and Kara Swisher
at the All Things D conference. When asked by Walt why they originally put their new OS on a phone and not a tablet, Steve said, "I'll tell you a secret. It began with the tablet." After working on the tablet OS which had a glass display and multitouch, another idea occurred to Jobs. "My God, I said, this would make a great phone ... so we shelved the tablet and built the iPhone
." And there you have it.