DisplayLink USB-to-DVI adapter review
 

Last year, Samsung released a 19" LCD monitor capable of being hooked up via a simple USB connection. To work its magic, the display uses an embedded video chip made by a company called DisplayLink that works like a sort of self-contained graphics processor. That's neat, but what if you already have a spare monitor you'd like to use via USB? Is there a cheaper alternative to coughing up the $300 or so for a USB display? As it turns out, yes there is. DisplayLink's video chip is also available in standalone USB-to-DVI adapters, which allow one to connect any monitor with a resolution up to 1600 x 1200 via USB.

http://techreport.com/articles.x/14057