After reviewing AVATAR, I happened to discover this documentary called Voyage to Pandora.
The video is from the Cosmic Journeys series and examines the cosmic neighborhood of Alpha Centauri in which James Cameron‘s fictional planet Pandora is situated. It does a great job at describing the actual science and technological challenges of locating and traveling to any of the planets in the Alpha Centauri quadrant.
The video may be played in High Definition and has some spectacular images of actual space telescopes and the movie AVATAR. If you enjoy documentaries about space exploration or the universe you will probably love this one.