The title might sound rather daft - if you have a laptop, why a portable screen? I'll try to explain: I travel a lot. I am studying for an MSc and have to reference a lot of documentation. The most efficient way to reference (IMO) is to have the paper on which one is working on one screen, and the reference material on another. So: Does anyone know of a portable (powered by USB?) screen about the size of a laptop that can be used as a second screen? Thanks in anticipation.