Comment on MPlayer OSX

The command-line version of Mplayer can easily rotate a movie, eg:
mplayer -vf rotate=1 mymovie.mpg
will rotate clockwise, see mplayer's documentation for more info.
The command line mplayer is included, and can be found here (for the intel version):
/Applications/MPlayer OSX.app/Contents/Resources/External_Binaries/mplayer_intel.app/Contents/MacOS/mplayer