Okay, this is about the neatest thing that you will see on Black Friday. Intel has been working on a system called OASIS (Object Aware Situated Interaction System) that combines projections with Lego.
This system uses cameras that can detect both objects and depth. As a result, it knows where the Lego toys are, and can even add a little bit of special effects with the practical application of some projectors.
I have a video of this OASIS in action after the jump if you want to see how it works, and it is the coolest thing to happen to Lego since the Mindstorms NXT.