“Improv Everywhere causes scenes of chaos and joy in public places. Created in August of 2001 by Charlie Todd, Improv Everywhere has executed over 70 missions involving thousands of undercover agents. The group is based in New York City.”
I would have LOVED to have been part of one of their latest missions, freezing in place in the busy Main Concourse of Grand Central Station. Check out this video on their web site to see the fun.