A while ago (April ’05) BBC News already had a topic on project Audioclouds by researchers at the University of Glasgow. The aim is to control gadgets using movement and sound. Motion is sensed using accelerometers, not via cameras. The coverage by the BBC led to a discussion on engadget about the desirability of such gesture-controlled gadgets. Most of the obvious pros and cons are given, as well as more careful arguments. Since then the project moved on, featuring contributions to lots of HCI conferences mostly.