
Gumstix is a company that makes computers the size of, guess what, a stick of gum. They currently have a kit that comes with a 4.3" LCD. The kit includes:
600 Mhz CPU
128MB RAM
USB Host
4.3" LCD
touchscreen
Micro SD card slot
3 RS-232 ports
10/100 Ethernet
http://gumstix.com/store/catalog/pro...roducts_id=202
They don't yet offer a touchscreen, but it does have 3 serial ports available. It shouldn't be hard to add a few buttons, or possibly even a small keyboard.
Edit: Yes it is a touchscreen!