Pepsi recently pranked a bunch of people in London by replacing one clear wall of a bus stop with an HD television screen. Then they played footage of the same street from the same angle, so it still looked like it was still just clear glass.
And while people were waiting for their buses, they made it look like crazy DISASTERS were happening . . . like a meteor hitting the street, and ALIENS attacking.
(Search for "Pepsi Max - Unbelievable Bus Shelter." The pranks start at :20.)