The Facade Printer is a computer-controlled paintball gun. It was developed by the German design group Sonice Development GmbH and can paint images onto a wall:
It consists of a two-axis turntable and a print head which is powered by compressed air. The printer shoots the picture dot by dot from a remote distance on a selected surface. Particularly inaccessable, formatless and uneven surfaces can be printed on. For example a building can be printed from the street, without having a complex scaffolding.
Gallery and Technical Info (in German) via GearFuse