A new accessory for your Smartphone which will allow you to use it as a notebook called the Clambook is on its way to the market by the holiday season
http://www.notebookcheck.net/Clambook-turns-your-existing-notebook-into-a-Padfone.76035.0.html
They should have two versions, the clambook and a "clambook cable converter" with extensions for external screen, usb mouse and usb keyboard. Obviously the "Clambook cable" would be the cheapest! ;D