Razvan talk about hooking Amarok to MySQL database server and create an MP3 file server. I this is an excellent hack:

When it comes to playing music in Linux, Amarok is one of the best audio players out there. It offers almost everything you need, from a clean, intuitive interface to a range of useful scripts. You can even put it on a server and give it a Web interface.

ObsidianMusic was previously known as amaroK Web Frontend. It is a collection of scripts that, combined with a MySQL database and the Amarok player, forms an excellent way of sharing MP3 files over the Internet or a small office network. All the music files in your collection can be played, downloaded, or streamed by a regular Web browser. Furthermore, ObsidianMusic offers search capabilities and music sorting, and can be customized using themes.

=> Create an MP3 file server using Amarok and ObsidianMusic