Dongle connects second display to PC
No need to change video cards.
If you hate having to change the video card in your PC to support multiple displays, here's a way that can help save the hassle. The Logitec LDE-SX010U, which is expected to be released in Japan in mid-March, is a USB-to-DVI dongle that lets you connect additional monitors to your computer via the USB 2.0 port.
The Logitec dongle supports a maximum 1,400x1,050 pixels, which is the standard native resolution for most 19-inch panels. Up to six displays can be connected to one PC, according to Akihabara News, though a more powerful computer is recommended as more displays are added.
Users can choose to activate the multi-display option for larger desktop real estate or the "mirroring" mode, which essentially duplicates the content on the different screens. A "90 degrees" option also enables the display to be rotated for portrait viewing. Unfortunately for Mac users, the Logitec dongle supports only Windows Vista, XP, and 2000.
(Source: Crave Asia)