The WiiSpray conceptualized by Martin Lihs at Bauhaus-University for his final diploma presentation enables users to bomb virtually. Martin Lihs explains the project in detail at the WiiSpray website:
http://www.wiispray.com/

The foundational basis for the project goes well beyond replacing real graffiti as an art form. Moreover, WiiSpray is to be seen as an interface to give graffiti a new virtual level surpassing tactile boundaries of the tangible world.