For its latest cool project, the merry pranksters of Improv Everywhere arranged for hundreds of people to stand along the Brooklyn Bridge at night and fire camera flashes in sequence, capturing everything on video from a fair distance away. I love the increasingly larger scale of Improv Everywhere’s missions.

But I thought I should note that on two different occasions back in 1999 and 2000, a group of my friends organized a very similar project at the top of the Empire State Building. Led by my pal Tom Igoe, a world-class tinkerer who teaches at New York University’s Interactive Telecommunications Program, a group of several dozen people gathered on the skyscraper’s southern observation deck to do waves of sequenced camera flashes.

The New York Times ran a story about the 2000 event a couple of weeks later. Both Flash-a-Thons were captured on video, the second from two locations downtown: one at the Tisch School of the Arts on Broadway and Waverly, the other from an apartment on East 18th Street. In the low-res compilation video below, the flashes go left to right and then right to left, and then there’s some assorted mayhem at the end.

You can read more about the 1999 and 2000 Flash-a-Thons on Tom’s site.