OK, so I don't keep up :-). I thought MP3 was a recording technique.
You're telling me it's a separate and distinct medium? I guess I'll
have to do a google.

MP3 (WMA or whatever) is the digital recording and playback of music. No more
little bits of plastic.
That is why RIAA has their panties in a wad over it. They aren't trying to
protect the music business, just the plastic business.
I haven't used a record, tape or CD to listen to music for almost 4 years. Once
you figure out you can have instant access to a thousand albums with the touch
of a button you wonder why anyone would.
I have MP3 players in all of my cars and 2 in the house. With networking the
house players can all be connected to a central server.