Codewave Software's MyTunesRSS is a free app for Windows and Mac OS X that sets up a server on your PC that will allow you to listen to your music collection from any web browser. It has quite a few features, including generating RSS feeds from your playlists (hence the name), playlist creation, library searching, and password-protection. One caveat is that it will only let you access MP3 files and unprotected AAC files (which excludes tracks purchased from iTMS), but the RSS feeds make it possible to listen to your music with any podcast-capable program or device, like a PSP.

[Via Lifehacker]