Some movies benefit from repeat viewings. The time travel genre seems like an especially ripe candidate for double-dipping--since the ending of such movies often alters one’s perception of everything that came beforehand, it’s tempting to go back and see how the logic holds up. In the case of the hit time travel movie, Looper, director Rian Johnson is way ahead of us.
As he did with his previous film, The Brothers Bloom, Johnson has recorded a commentary track that is meant to be heard in-theater. (Of course, he strongly cautions against listening to it on a first viewing.) Considering that the new film starring Joseph Gordon-Levitt and Bruce Willis has a much higher profile and a plot better suited to directorial untangling than Bloom, Johnson was besieged by requests from fans to repeat the experiment.
The Looper commentary is a totally different track than the version that will be included on the eventual DVD/Blu-ray release. This version is more technical and detailed, meaning don’t expect any anecdotes about how the actors got along or what the weather was like during filming. There’s an introduction up top that instructs users on how to sync up for the optimum viewing experience. Just try not to scream out "I knew it!" when the revelations start pouring in.