I wanto do losslessly join the mp4 video clips shot with the phone.

I usually shoot most clips in the same resolution (often 720p).
So it is a waste of time, energy and above all quality to get them joined with software that rencodes (transcodes) it.
It is ridiculous to shoot in HD and re-encode - the crispness of the original image is gone forever.

I would prefer a solution that works on the mac, however windows/linux are ok too.
On the phone, the samsung video maker seems to re-encode, and anyway the interface is limited.

I tried (on a set of mp4 clips of same resolution)
MP4Box http://gpac.wp.institut-telecom.fr/mp4box/
SimpleMovieX http://simplemoviex.com/SimpleMovieX/index.var
MpegStreamClip http://www.squared5.com/
and of course Mac's own iMovie09

MP4Box often crashes, SimpleMovieX resizes to small, MpegStreamClip strips the audio away,
iMovie09i re-encodes.

my best results so far is to use MpegStreamClip to save in .mov (with multiple audio streams, not very portable)
then open the mov with SimpleMovieX and export it to mp4 - video passthrough, re-encode audio with best quality.

if anyone has an easier solution, I'd welcome it!