Hi,
I work for JVC and would like to try and help.
To clarify, The JVC Everio camcorders will work very nicely with iMovie '08 or iMovie '09. As was explained in the post above, you connect via USB, and select "Playback on PC" from the JVC camcorder USB Menu. Then you launch iMovie '08/'09.
This is true for both standard definition Everio models that record MPEG2 video (.mod file extension) and high definition Everio models that record in AVCHD format (.mts file extension). For HD, you do need to make sure that you have an Intel processor.
If you have an older version of iMovie, then you will generally need conversion software. There are several good choices, although for many people it is better, and easier, to simply update to the more recent version of iMovie.
I hope this helps.
Chris