The Great American Smoke-Out?

by guestofaguest · April 22, 2009

Thousands of people gather on Norlin Quad at the University of Colorado in Boulder, Colorado, where the April 20 date has been famously marked for years. This photo was taken at precisely 4:20 PM, when the entire crowd exhaled at once. We're not sure what the best thing about this photo is, that it actually happened, or that it's part of a special feature on Time.