[youtube=http://www.youtube.com/watch?v=jwMj3PJDxuo&rel=1]
Over 200 improv agents gathered at New Yorks Grand Central railway station, for a large scale improv prank. They were given instructions that, at exactly 2:30PM, they would just freeze – doing things that normal people would do, and just freezing in the middle. There were people who had a water bottle to their lips and just froze. People who bent to tie their shoe laces and just froze. They froze for exactly 5 minutes, much to the amusement of the passers-by. I think the security and maintanence people were pretty shocked too :).
Click here for a more detailed report.