As fun as it would be to believe there's something supernatural about these curvaceous Ghost Tops that look like they're slowly turning invisible as they spin, the only magic involved is the 3D printing machines that create them from metal instead of flimsy plastic.
For $20 to $25 you can order one from Shapeways in of several metal finishes that make the tops look like they're actually made from gold, nickel, or brass.
The unique twisted wire design that makes the tops appear to disappear when in motion also happens to have a very efficient spinning geometry, and with a strong twist they'll apparently stay upright for about a minute-and-a-half. So get one for work, and before you know it you'll have killed a solid half hour of an afternoon that seems to be dragging on forever. [Shapeways via Notcot]