Up to four monitors to a single PC/Intel Mac

The OWC USB 2.0 Display Adapter from Other World Computing allows you to add an extra display to Intel Macs or Windows PCs using any standard USB 2.0 port. The adapter connects to HDMI, DVI, and VGA equipped displays (including projectors) in 32-bit color at resolutions up to 1600x1200 or 1680x1050 digital. Included driver software means that the display can be used in mirror mode or as an extension of the desktop. Up to four adapters can be attached to a single computer.
(Source: Macintouch) | Cost: US$99 | Requires: Mac OS X 10.4+ or Windows 2000 & up | For further info...