In this video the two people are holding motion capture pens and using them to 'sketch' in the air. The Nintendo Wii controller could perform a similar task theoretically. They sketch up some furniture and then load the sketchs into a rapid protype printer and print up the furniture. The video itself is somewhat of a fakeout because the video has computer generated graphics where the people sketched but they themselves can't see what they are sketching in real time. It might help if they had a semitransparent display they could look through and actually see what they are sketching instead of only seeing it in their mind's eye. I'd think you'd have better like making furniture with one of those 3D lathe softwares and then rapid prototyping the object instead.