We know. That's crazy. And, impossible.
Some crafty students in MIT Media Lab's Tangible Media Group, however, have done just that. Their inFORM 3-D display — well, more like 2.5-D — instantly produces physical, topographical forms. According to the authors, "inFORM is a Dynamic Shape Display that can render 3-D content physically, so users can interact with digital information in a tangible way." Think of one of those pin art toys from your childhood, only one that's a helluva lot smarter.
A computer connects to small motors attached to each of the pins below the table, while a remote camera tracks the movements of the user and translates them into a shapes. Just watch this:
Okay, so it's mind-blowing. But, how might it work outside the lab? Well, video conferencing is one potential application, as the demo above proves. The inFORM display could also be used by architects and industrial designers to rapidly prototype low-resolution objects, as well as collaborate on them remotely. It also has potential in the medical field, as a medium for presenting information like CT scan results.