I’ve been fiddling around with the raspberry pi and an old Atrix 4G laptop dock. Lots of people show how to hook them up on the web, and if it wasn’t a little cumbersome with the cables it would qualify as a super thin netbook.
Still haven’t decided what to make out of the raspberry pi. It was fun hooking up the pi to my tv using the usb port on the stereo and a regular hdmi cable. I suppose you could use a usb port from your tv if it has one like the computer on a stick devices.
I used this tiny keyboard – touchpad to browse around: