Here is a recording of Professor Jim Al-Khalili of Theoretical Physics and Chair in the Public Engagement in Science at the University of Surrey giving a lecture on time travel separating the facts from fiction. Its a bit long but it is a great lecture and he really breaks it down.
That was an entirely entertaining, and intensively enlightening view. I sort of now want to download the whole thing and put it to a DvD just to add it to my current movie/video collection.