It will probably only do cloned displays. I think they are useful in offices where you want a customer to see what you see without having to turn your monitor. I've also see a karate school here in town use one to show pictures of the students on two monitors, one facing out the front window and one facing inside.
No. It is a splitter only. In other words in can take the "out" image from the computer and show it on 2 monitors. It's dies not have the "smarts" or the processing power to do a true dual monitor setup.