This one is trickier than I originally thought. I was going to go for Iron Man by Black Sabbath because I was fairly sure it didn't feature in the 2008 Iron Man film... but according to that pesky Wikipedia, an instrumental section is used at the start of the end titles. Curses, back to the drawing board.
Second choice then is High Fidelity - the film and the Elvis Costello track:
So here's a trailer for the film (with Jack Black stealing the show):
And here's the track:
Phew! I think this may be a fairly limited set of films. Can any one find any others or am I going to have to widen this out a bit?
{Update: Just changed Day 11's of the 30 Day Movie Music Challenge to (hopefully) make it easier. It now simply reads, "Music that shares its name with a film title." }