If you don't recall, Google April Fool's Day pranked the tech community by announcing Gmail Motion. Evidently the members of University of Southern California Institute for Creatie Technology MxR Lab were laughing at Google rather than with them.
USC's ICT MxR lab develops the Flexible Action and Articulated Skeleton Toolkit (FAAST), a Kinect-based motion-recognition system that allows you to develop motion-controlled interfaces for application commands, amongst other things.
The prank was on Google, as the MxR's duplicated Gmail Motion entirely, including all of the ridiculous gestures, using a system they call Software Library Optimizing Obligatory Waving (SLOOW).
Still love that the stamp slapping works.
Good work guys! Video below: