DESIGN/ADVERTISING: Billboards to be proud of

Since blogging about the banishment of outdoor advertisements in Sao Paulo I decided to try and find some examples of billboards that have gone above and beyond what people expect from a large advert. Below are three examples of where the billboard has been turned into a carefully constructed piece of design, used to engage the audience, to make them stop and think and to remember not only the brand on the logo but their idea.

I especially like the Economist billboard, I think it's a quick, clever idea that is brilliantly executed.