If you're famous at work for doing the impossible, it's time to deck out your desk with something fitting.
This limited-edition M.C. Escher Waterfall Sculpture is available on ThinkGeek for an impossible-to-believe price of $59.99. Only 500 of the sculptures exist, so you should act quickly if you want to get in on the fun.
The sculpture, based on the famous M.C. Escher woodcut, is just six inches tall. That puts it squarely in the running for the object with the most ability to blow your mind per square inch.
Alas, the water in the sculpture isn't real. As such, it does not defy the laws of gravity by flowing upward. You'll need a wizard to help you with that.