When Google launched their German version of Google Video they decided to do a bit of advertising for the product. Google don't usually advertise much as they have tremendous word-of-mouth and brand recall. However this didn't stop them from using a very innovative (in my mind) billboard campaign.
The billboards were mostly clear, with a little strip on the top and bottom of the frame to make it look like watching a video in Google Video. In the search term box were some words describing the scene passersby would see through it.
Check our the video here: http://www.youtube.com/watch?v=Um-WL7FRANM