Just saw this last night. It stars Chris O'Dowd, the Irish guy from
The IT Crowd, in what is a short-ish (about 75 minutes) story about a science fiction fan obsessed with time travel who meets a time traveller, and embarks on, well, a movie-long journey with his two friends in a pub toilet. Really enjoyed it. Silly but worthwhile.
Trailer, though I don't particularly think it captures what it's "about":
http://www.youtube.com/watch?v=WBV340x3GcA