How many times can you relive a train explosion?

Duncan Jones, director of Moon, has just released the first trailer for his new film, Source Code. In it, Jake Gyllenhaal has to relive the last 8 minutes of another man's life over and over.

This flick looks like a strange cross between Groundhog Day and Speed - which could be awesome, or could be just a little gimmicky. Since it's Jones and Gyllenhaal, though, we're giving it the benefit of the doubt.