Ahaa,

Again, not quite the solution you're looking for, but might be worth a look:

http://www.microsoft.com/windowsxp/u..._multimon.mspx

Basically the second part of this article explains about a program that allows a laptop that is networked to a desktop, become a second or third etc monitor. The obvious restirctions are that the laptop will still need to be in one piece, and it needs to be networked to the desktop, however the program can run on older now very cheap laptops!