Are there any options to upload music files from a computer other than those running a flavor of Windows? My Central came with a one page flyer that lists Mac OS and Apple's iTunes logos at the bottom. But I can't find any reference or any way to actually do anything other than with Empload on windows.

Yes. The most recent "prerelease" versions of Jemplode (found at www.jempeg.org ) can connect to the HSX-109 and send files to it, just like Emplode does. It is essentially a Java version of Emplode. It only works over ethernet and HPNA, not USB, though.

Mike and I are currently trying to figure out why it's slower sending files from Jemplode than it is from Emplode, but at least it works at the moment.

Jemplode is a very neat little program, check it out.