Fake U2 Concert.

This is pretty badass.

http://www.improveverywhere.com/mission_view.php?mission_id=48

Basically, a groip called "Improv Everywhere" decided to put on a fake U2 Concert on a rooftop in New York. In full disguises, they were able to play a few songs before being shut down by the local Police. Some onlookers believed it was real, some knew it was fake, the distance and the quality of the speakers were able to fool many into thinking it was the actual band.

This, is awesome. I wish I could do things like this.