There's no official information as yet on Samsung's CX940UX USB monitor (apart from a rather cheesy picture), but it seems rather interesting, especially to application users (gamers will probably find it's too slow).
USB2 is 480MBits so even one monitor per port would be limited to AGPx2 (533Mbits) speeds.USB3 (due next year) could up this to 4.8 Gbits per second. PCI-Express 16x is the current graphics standard and is capable of 2500Mbits.
It is a 19 inch PC monitor, from the Syncmaster family, that you can plug directly into your computer through the USB port. This monitor can control 6 others, all linked via the PC, and apparently you won't need any additional graphics card or new drivers to manage the multiple screens operations, their baby will do it all.If that wasn't enough, the "CX" sports a couple USB ports so it can also be used as a mini-hub.