$160 PowerPC Computer

[Dan]

Or this:
http://nvplanet.com/modules.php?name=News&file=article&sid=2551

Telegnosis? USB 2.0 VGA adapter allows to display 640x480, 800x600 and 1024x768 resolutions with 8/16/32-bit color depth. The device will not be suitable for gamers as it does not sport Direct3D, however, the target market for the product seems to be business-oriented customers who need some additional capabilities from their notebooks or desktops.

Or a direct LCD-driverinterface for USB, I bet that there is many of those things around.