The Tangible Table is a new table platform by Manuel Hollert and Daniel Guse:
"Our goal was to build a working prototype of a tangible table-based user interface. In contrast to a simulation, this environment facilitates the evaluation and testing of user interactions. That’s why the visual components on the table surface (such as scales) are quite basic and rough. The principles of interaction and graphical behavior had higher priority."
The technical implementation is described here with a description of how they used fiducial markers. Also, check the video
