Billboard Arts Project
more photos can be found at
http://www.flickr.com/photos/billboardartproject/sets/72157630811102310/
and a video can be found at : http://www.youtube.com/watch?v=FIGuNzOjNbE&feature=BFa&list=UUmVsJp7-w-n6vj3QALtdqcg
(with my billboard being at about 8:17)
Photo by The Billboard Art Project