For the past few months, I've been using the SLiMP3, from Slim Devices. It is a rather intuitive device - it is a home entertainment device that plugs into your stereo and your LAN. The device then can play any MP3 file located on your computer.

An included remote control and a beautiful display make it easy to find the songs to play from your collection. The device itself only decodes mp3s internally; all other processing is done on your computer - thus there are no real limitations to the number of files it can play. The server application is written in Perl and thus it can run on nearly any operating system. Aside from the remote control, you can also control the player from the server's built-in web server.

The server software is maintained as an open-source product; because of this new features can be expected down the road. I've done a bit of experimenting with using the display for other things such as an email checker, caller ID display, and news ticker.