This very interesting outdoor campaign for Google Video Germany used a billboard imitating a real-life video player that captures the life as it happens. The tagline is "any film you can imagine", a simple message that encourages people to search for videos and to upload their own videos. AdFreak has an interesting explanation for the unusual idea: the see-through billboards suggest "that online video presents life in all its glorious randomness".
It's not very clear if the campaign was launched before or after the YouTube acquisition, but the fact that the video embedded below is from YouTube tells a lot about Google Video's success.