Just when you thought Concorde was gone for good, a group of French and British investors are talking about bringing the world's first supersonic airliner back to the skies. In mothballs (or sold off piece-by-piece) since their last flights in 2003, the group wants to resurrect Concorde for what they're calling "heritage flights." It's unclear exactly what "heritage flights" are, but the murky concept might have something to do with the opening of the 2012 Olympics in London.