well thanks to Adrian and Vincent I finally got the python scripts running to copy from a MZ-N910 to my Macbook with Snow Leopard and I'd like to give a little feedback on my experience as a simple user.
1. python has to be called directly from /opt/local/bin/python2.6 instead of ./ as the installed version of Python is apparently not looking for the installed extra packages at the correct location.
2. The instructions for Mac OS X on https://wiki.physik.fu-berlin.de/linux-minidisc/doku.php?id=netmdpython do not explicitly mention adding <sox install dir> to $PATH in .profile.
3. The instructions mention audio card with analog input as a requirement, but somehow I overlooked this and wondered why SoX wasn't picking up any sound. Maybe you could make this a little clearer
4. SoX v14.3.1 would not record, not even with a simple sox -d xxx.wav
5. SoX v14.3.2 records, but gives out a lot of "sox WARN coreaudio: coreaudio: unhandled buffer overrun. Data discarded." errors. I realize that this isn't your problem, folks, and I'll keep an eye open for a new release.
Now, where was that "Donate" button again...