MyTunesRSS is a Java application that runs on any platform that supports both Java 1.5 and iTunes. It makes an RSS feed of your iTunes library, making each song into an individual podcast. The application is both the server and the RSS feed manager. You can now access your iTunes music (mp3 and unprotected AAC files) from any computer that has a web browser and that can access your network. You can also make the access password protected.
I haven't tried it yet, but plan to soon. I'll report back when I do.