Love these two artists working together: JR and Liu Bolin.
JR is a French artist that I only recently learned about from a fellow student. He's know for "pervasive art" - printing massive close-up portraits of people pulling goofy faces and putting them up on the walls of buildings for anyone to encounter and interact with. Here are some of his installations in a favela of Rio de Janiero, a slum in Kenya, and from his project Face2Face, with portraits of Israelis and Palestinians displayed in both countries.
the above photos are from his website http://jr-art.net/
And Liu Bolin is somewhat of an internet sensation these days as the "real-life Invisible Man". His photos in which he's painted himself into the background are pretty remarkable.
all above photos can be found here
So I thought it was pretty neat to see them collaborating. In the top photo, Liu Bolin painted JR to blend in to his own work.