Freeware MP4 editor?

[rockyhill]

HI, I have a lot of MP4 files and I want to edit mp4 videos. Basically I want to be able to take lots of small sections out of all of them, and put them all together in one video, hopefully MPG or something. I would also possibly like to have the option of sound and video fading each bit in and and to make it smoother. I notice that Windows Movie Maker can do these fades, but won't accept MP4 (and of course I can't seem to cut the bits out in that program anyway). Does anyone know of any simple mp4 movie editor programs which might do this?