This is something we found at the Escher Museum in the Hague, Netherlands. I love the experience of Multi-touch on a very large screen. The final image is shown below, taken from here.

Of course, I strongly recommend checking out the mind-bending work of this guy.

Mr. Jobs himself marketed multi-touch as awesome.

I plan to write more soon about what makes these interfaces powerful. Hint: It’s an idea called Direct Manipulation.