I have recently seen the movie Primer and was impressed. In short, it's a individual film made with a budget of seven thousand dollars, by a self-taught director, producer and actor, Shane Carruth. IMDB and Wikipedia have more information, the film also has a website so I'm not going into details.
Basically the idea is as follows (basically almost zero spoilors): four guys are engineers but produce electronic devices in their free time, they try something to block gravitational waves but end up with a time machine (the tagline is relevant: "What if it actually works?"). This works in a special matter, as explained best on Wikipedia. The story revolves around time travel and the paradoxes this implies.
Assuming you have seen the movie or at least know the time machine works in the movie, I wish to hear your thoughts on this time travel idea. [The movie is terribly hard to find, and virtually impossible to get in Romania, so I must be ashamed for retorting to piracy...]