http://GraffitiResearchLab.com Awesome video from the boys at graffiti research labs. Projecting graffiti with a laser pointer on the side of a building... CRAZY
The song is Don Carlos - Pass Me The Laser Beam
and heres how it works
"In its simplest form the Laser Tag system is a camera and laptop setup, tracking a green laser point across the face of a building and generating graphics based on the laser's position which then get projected back onto the building with a high power projector."