Steven Spielberg
In maybe the smallest cameo ever done, Steven Spielberg can be seen for only a moment in the background of the sequel to Indiana Jones: Raiders of the Lost Ark. The movie, The Temple of Doom, shows Spielberg in the huddle of missionaries seen during the Shanghai airport scene while Indiana Jones unknowingly gets on a fake flight. This scene also depicts Dan Aykroyd as Weber, a two-for-one cameo!