The USB 2.0 to VGA/DVI/HDMI Multi-Display Adapter allows you to connect an extra monitor (CRT,LCD,Projector..)to your desktop PC or laptop’s USB port.The connected monitor can be configured to either clone your primary screen or extend the Windows desktop allowing visibility of more applications at the same time.
http://www.digsell.com/usb-multi-display-adapter-for-computer-add-on-a-second-monitor.html