I have just released a small utility – this one can join to mpeg4 files into one
Supports MP4 and M4V files. Files must be the same encoder settings , and it will seemlessly join them with no reencoding – its fast and simple, only a few minutes for a couple of hours total files.
Download, unzip, run the exe. point to the first file, the second file, choose a save file name and his go …thats it.
NOTE – THIS WILL NOT KEEP ANY METADATA YOU HAVE ADDED TO THE FILES BEFORE JOINING THEM – YOU WILL NEED TO RE-ADD METADATA OF REQUIRED.
Videoscripts 
is it possible to join more than 2 files?
Currently only two files only. But its easily scalable if you have a need for more files. Let me know.
I would like to be able to do a list of .mp4 files and would be interested in such a version.
Thanks,
Gene
Ok, it’s on the list. Subscribe to the updates posts and you will get notified when I get it done. Likely 1 month away though.