I guess it's just natural that folks pondering the future of the GUI would turn to 3D spaces. After all, clearly 3D has played a dominant role in the most important software genre: videogames. However, past efforts towards the "3D Desktop" have seemed impractical. Nonetheless, I think BumpTop, which utilizes a tablet PC and pen tool, is on to something big. Watch the You Tube and see what you think.