Improv Everywhere

In a mix of performance art and old-fashioned pranking, this guerilla comedy collective captures attention through its well-executed manipulation of public space.

Next time you see somebody without their pants, ask if they're part of Improv Everywhere (before you call the authorities, of course).

Editorial note: Whoa! You've found a super-old post here on BuzzFeed, from an earlier era of the site. It doesn't really represent where we are anymore, and may in fact be totally broken, but we're leaving it up as a part of our early history.