Desktop Multiplier

Use Your unused computer monitor of the house. You can easily convert that unused monitor into a proper PC by just attaching it to one of your existing computers – no additional hardware required.
Here is A Video :

A free software called Userful which is essentially a Linux Live CD. You connect the two monitors to one computer, pop the CD inside and boot.

1.Now two users can surf different websites,
2.Access their personal emails,
3.write documents and more at the same time on their personal screens.
4.They’ll also have access to common devices like the printer and scanner attached to the main computer.

This solution may appeal when you have basic computing requirements or have no budget for an extra computer.

Links:
Userful Desktop Multiplierhttp://userful.com/products/free-2-user

Live CD http://userful.com/live-cd/download