Laser Message on Building, Barcelona
This text "WE [heart] LASER", was projected up onto the side of a building in Barcelona by the subversive tech group, Graffiti Research Lab. They projected up a number of messages onto various building sides until they were stopped for doing it on the side of a Starbucks.
Their cool projection system allows someone to use a laser-pointer to sketch out a message on the side of the building -- the system captures the path of the laser-pointer and broadens the strokes and even applies styles like paint-drippings to what's written.
This picture was used to illustrate my article on Laser-Projected Graffiti Ads on Buildings.