Are the CF microdrives you're talking about the same microdrives that you can find in the Muvo's or Ipod mini's?
As described here.
Just curious, I saw this show a while back and I'm shopping for memory for my Axim now.
Edit: found more information.. These particular microdrives are selling for $168 off of Hitachi's web site, so it's not really economical to tear a player apart anymore to get the drive.