Oh, also, 'net-md' has been available for a few years, with a Net-md you can do very fast transfer to pc. The downside of Net-mds is, a lot of them dont have mic inputs (some do, the minidisc site will help with specs).
Clinton also talked about HI-MD, well I haven't really looked into these, I think they can record music, compressed with mp3 format.
They probably just use ATRAC to do mic recording tho, I don't know...it's worth looking into if you want a fast transfer to PC and huge disc storage, Me, I don't mind just plugging a cable from the Md headphone (or line out) socket, into my soundcard and just letting it play through. It all depends on how patient you are and what volume of field-recorded stuff you actually want to put on PC.
moo