There's nothing quite like a mystery, and we flock to thrilling movies and agonize over cliffhanger endings to TV episodes. Even more fascinating than a fictional mystery is the tale of a real-life disappearance. The words "without a trace" just seem to make us want to learn more. Maybe, we think, we'll even be able to solve the mystery ourselves.Join us as we remember Jimmy Hoffa and others who have famously disappeared… maybe you'll form some theories of your own. Click any photo to learn the facts.