Using the Flexible Action and Articulated Skeleton Toolkit (FAAST) software and a Kinect sensor, USC ICT lab successfully turned Gmail motion into reality!
"This morning, Google introduced Gmail Motion, allowing users to control Gmail using gestures and body movement. However, for whatever reason, their application doesn't appear to work. So, we demonstrate our solution - the Software Library Optimizing Obligatory Waving (SLOOW) - and show how it can be used with a Microsoft Kinect sensor to control Gmail using the gestures described by Google."
Google's Gmail motion