I have been struggling with figuring out the easiest way of converting MPEG-2 .MOD files coming out of a JVC Everio HD camera to something else, and finally found a good solution in Squared 5 - MPEG Streamclip which allows for converting these files to more or less all codecs that are available on the system. It is also a good idea to rename the .MOD files to .M2V or .MPG since this will allow QuickTime to play them (without sound, since they are demuxed…) or even better with VLC (with sound!).