Are you a geek? Here's one way to tell: if you think the below video is undeniably awesome and you would like to immediately copy this idea, then you, my friend, are a geek:
I wish I had some idea how in the world they were accomplishing this. The laser projector part seems pretty straight forward, but the laser pen interface has me stumped. I suppose they must have some kind of camera rigged up to a computer to track the green dot as input, which then instructs the projector to render along with the dot.