My wife has a Displaylink USB adapter attached to her Macbook so that she can run two external 20" screens. It's great - it's fast enough for everything that s

My wife has a Displaylink USB adapter attached to her Macbook so that she can run two external 20" screens. It's great - it's fast enough for everything that she does (even for videos etc). You only notice you're on a USB adapter when you drag around a window very quickly, or you open Dashboard, and even then - it's not that bad. (is this really an Ask YC question though?)