There's a movie teaser line that you may have seen recently, that goes like this: "What if you had to tell someone the most important thing in the world, but you knew they'd never believe you?" The answer is "I'd try." The teaser's actually for another movie, but that's the story that's told in the documentary "An Inconvenient Truth": it starts with a man who, after talking with scientists and senators, can't get anyone to listen to what he thinks is the most important thing in the world. It comes out on DVD today.