Maiden Group in London has an idea and actually did it to place a large number of 100m Bluetooth transmitter behind a billboard, and beam the advertisement to whoever accepted it. Before it send the clips to the phone, it will ask the permision from the phone user first.

Ignoring adverts is about to get a lot tougher with the development of billboards and advertising posters that use Bluetooth to beam video ads direct to passing cellphones. As people walk past the posters they receive a message on their phone asking them if they wish to accept the advert. If they do, they can receive movies, animations, music or still images further promoting the advertised product.

The posters detected 87,000 Bluetooth phones over a two week period, of which about 17% were willing to download the clip, says Scott.

http://www.newscientist.com/article.ns?id=dn7883