They May Not Smile; But Ask Nicely, and You'll Get a Pirhouette
Heh. This is clever. For the New Directors Showcase at Cannes, Saatchi & Saatchi released a video in which some ordinary guy barks marching orders at the Buckingham Palace Guard -- and, amazingly, they obey, even when he asks them to do little leaps, jump on each other's backs, dance to reggae and "RIDE 'IM LIKE SEABISCUIT!"
At this point the stunned crowd gets the sense that this is a stunt, and there is much cheering and carrying-on.