Medusa is a Microsoft Surface that has been instrumented with 138 proximity sensors. These proximity sensors enable the Surface to sense the users around it, as well as the hands and arms above its display. Not only are these sensors inexpensive and simple to configure, but also they enable an integrated hardware solution, without requiring any markers, cameras, or other sensing devices external to the display platform itself. As Medusa has an awareness of users’ locations, it can for example, identify touch points by user, and disambiguate between touches made with left or right hands. This video demonstrates a number of interaction techniques that are now possible using this information. Medusa’s additional sensing is meant to enhance the touch sensing of the underlying multi-touch tabletop, rather than to supplant or replace touch-based interaction.