Tunick has been doing this all over the world for several years. Do a Google image search on the name, and you'll probably find his own home page. He used to have some really high-res .jpgs of his "art" posted, but it's been quite a while since I looked him up.
It's really kind of "old-hat" by now. The Brits should be insulted that it took him so long to get to them.