http://gizmodo.com/5062343/olo-wants-to-fuse-the-iphone-with-netbooks

I am skeptical about this particular project, but this is definitely going to exist within the next 3 years. The iPhone is probably already powerful enough to power a full computer. 600 mhz, 16 GB flash, decent battery life, seems good enough to run barebones XP or Ubuntu.
The implications are game changing. The computer would be the most portable computer possible because it won't have any guts. It would be able to be used for long periods at a time (maybe even powered off the phone battery if batteries improve some more). Internet 24/7, a complete workstation.