Free .mp4 cutter?

Does anyone know of any free applications (and I mean entirely free, not something annoyingly restricted) I can use to cut an .mp4 file? I've just got Bumblefoot's Normal and the second to last track has 30 minutes of dead silence that I'd quite like to cut out, as it just takes up unneeded space on the old iPod (which nowadays is becoming dangerously full). Thanks very much!

I use mp3Trim for my Mp3s. Not sure if it works for MP4s.