This is the most amazing touch screen system I have ever seen. Watch the video to see it in action
this is an older video
check out how he moves the photos around with two fingers to rotate etc.
You can also go here for a good back story on the inventor, Jefferson Han, from the magazine Fast Company
They have a newer video of a bigger screen with two users. Unfotunately you have to watch an advertisement. If anyone can find this video somewhere else please comment.