No Shirts at Improv Everywhere
http://www.improveverywhere.com/2007/10/17/no-shirts
"For our latest mission, 111 men of all shapes and sizes shopped shirtless in the Abercrombie and Fitch store on 5th Avenue here in New York."
Improv Everywhere Mission: The Moebius
http://www.improveverywhere.com/mission_view.php?mission_id=30
"On Saturday, March 22, 2003 Improv Everywhere agents created a living moebius strip in the Astor Place Starbucks. Seven undercover agents meticulously repeated a five-minute slice of time for twelve consecutive repetitions."