So I just saw Improv Everywhere's latest "stunt" where they took about 207 participants, went to Grand Central Station and froze at the exact same instant. They stayed that way for 5 minutes and unfroze again. It was the coolest thing to see! After you get over the fact that the majority of New Yorkers are unfazed and walk about like they see that type of thing every day, you start to see the positions that the participants froze in...and the reactions of the surrounding crowds.
I found the video on MSN video and it's titled "Frozen Grand Central". Check it out!