Image via Toshiba
"While notebook hardware has steadily improved over the years, outside of the recent MacBook Pro with Retina Display there haven't really been any moves forward in improving desktop real estate in some time. In fact, for productivity-oriented users this continues to be a major reason for sticking with a desktop setup (if not a desktop system): more monitors, more space to work in. This fact of life has resulted in a bit of a niche market in the form of small, USB-powered screens.
We've tested both of GeChic's OnLap monitors and found that while they were flawed in their own ways, they were still able to expand useful work space without incurring too much of an inconvenience in terms of size or power requirements. Yet GeChic's screens need an HDMI or D-SUB port in addition to a USB 2.0 port for power, and if for one reason or another your notebook doesn't offer one of these, you're out of luck. Enter solutions based off of DisplayLink's USB technology, which are able to add another screen driven entirely over USB. Solutions like the screen we have on hand today, Toshiba's catchily-named 14" USB Mobile LCD Monitor." via AnandTech