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." (less info)