Don't be concerned by the blurb on the Casio DV-01 Digital Voice Recorder's box. It might say that the DV-01's software is for Mac OS 8/9 only, but if you switch on the device and then connect it your Mac's USB port, it will mount itself like any hard disk -- no driver software required. Simply drag the .wav files from the DV-01 to your Mac and then play them with iTunes.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030206060535464