I just saw someone pulling a "Marty McFly" via a stationary webcam broadcast from Duval Street in Key West. If you look at the camera, you are looking from Sloppy Joe's bar toward the other side of Duval Street and the intersection at Greene Street. A van driving north on Duval (left to right) and turning left on Greene had an additional passenger: some guy on a skateboard holding on to the ladder on the back door.

For those who do not remember, at the beginning of Robert Zemeckis' 1985 time travel hit Back to the Future, Marty McFly (Michael J. Fox) gets from Emmett Brown's home to downtown Hill Valley by holding on to various vehicles whilst riding his skateboard.