Multi-touch computer interfaces.

Now, my idea was the "Computer Aided Gaming Table" and relied on sound to do multi-point positioning (I have no idea what they use). Also, my surface was to be shared by several people, and I thought that, in order to save money, I would project the image onto a large surface.

But these guys actually made it work. This is the most exciting computer hardware advance I've seen...ever.

BTW, some would draw paralells with the fake UI in the movie "Minority Report" but I think that doesn't do the Multi-touch idea justice. The fake MR interface used far too many large body motions, which just aren't useful.