Please note, though, that MPEG Streamclip will NOT work with .MOD files to convert if you don't have iLife '08. If you have an earlier version of iLife, you must go to Apple's online store and purchase the Quicktime MPEG-2 plugin, and after that MPEG Streamclip should work fine.
For the record, .MOD is a form of MPEG-2 file that is program stream format. It interlaces audio and video in intervals in one stream/timeline, if you will. MPEG Streamclip, given the right tools from Apple's MPEG-2 Support (which is included in iLife '08), can disassemble the pieces and reassemble the video and audio linearly in video and audio tracks for whichever format you want to make it.
I just find it frustrating that better support for the file format isn't given even with Final Cut, since it is a widely used consumer video format. The only other supported options are to buy a twice as expensive HD camcorder so it writes in HDV/AVCHD, or get a camcorder that writes to a Mini DV tape - which is getting phased out and less support from Apple, as FireWire is being taken from their computers (See the new MacBook). There's a huge gap they're missing that really should be filled in. I don't think it should take more than a small update to make the codec available system-wide, rather than confining it strictly to iMovie '08 (correct me if I'm wrong).