On a plaza outside a hotel in Culver City, Calif., four people are stalking each other with PlayStation Move controllers. The devices look a bit like microphones, with glowing orbs on top lit up in pink, yellow and blue.
Video game designer Douglas Wilson is holding a portable speaker, blasting Johann Sebastian Bach's Brandenburg Concertos.
From afar, this looks like some sort of public performance art. But it is actually a high-tech combination of tag and musical chairs, called Johann Sebastian Joust.