Not strictly speaking anything to do with editing music (although I think it can do that) but I've just been trying Avidemux (http://www.avidemux.org/) which is an open source (and hence free to download) simple video editor.

I've only tried simple cutting so far - I used it to chop the end off a little vid I took yesterday on my still camera when I forgot to stop recording so the last 3/4 of it shows the ground! It did this task pretty easily.

Anyone else tried it?