Urballoon is a projector tethered to a float with wifi web access that broadcasts images onto the streets from 3 stories up. Anyone can submit images online for the project at their site.
Subcreation submitted these images:
to the project.
If you're in New York on the evenings of the Oct. 1-3, you can see it in action at the entrance of the City Hall Park as part of the spectopolis event.