Erik Johansson and Adobe set up a TV in place of a bus stop ad display and connected it the Johansson’s computer. As people waited at the bus stop, Johansson Photoshopped them into ads on the display for some great reactions by those waiting.
Photoshop Live Retouch Prank Puts People in Ads at Bus Stop While They Wait
[youtube http://www.youtube.com/watch?v=BRAM8MpqIeA&w=640&h=360]