I first read about this months ago in the NYTimes Magazine (at least I think I did). It has been making its way around the web recently and I thought I’d add to the sharing. Swedish design group Front has a process where invisible pen strokes in the air are recorded by Motion Capture and then turned into digital 3D files which then become real through a process called Rapid Prototyping. The video below illustrates the process awesomely, and you should also check out their website, as some of their other work is pretty awesome too.
Sketch Furniture - video powered by Metacafe