Today only. Newegg has the SIIG JU-VG0012-S1 USB 2.0 to VGA Pro USB to VGA Interface External Video Card for $35 with free shipping. Connects via USB 2.0 to add an additional VGA output (up to 1920 x 1080 resolution) to your computer.
With the 2.0 unit, though, it's perfect for opening giant spreadsheets and most other things you'd do with a multi-head machine. And at this price, why not?
DisplayLink chipset highly recommended! I own a few of these for various uses, and they're super handy. Don't expect really smooth video playback on the USB2.0 version, though, get the SuperSpeed product for that:
http://www.everythingusb.com/targus-usb-3.0-dual-video-adapter-21477.html
With the 2.0 unit, though, it's perfect for opening giant spreadsheets and most other things you'd do with a multi-head machine. And at this price, why not?