Currently, many employers are very negative on the idea of music being played at work, due to concerns about copyright infringement. While we may not be able to legally get popular music for free at work, we *can* enjoy it at a very reduced cost.
It seems that it would be a worthwhile idea to modify one of the many streaming audio servers out there, such as Shoutcast, to support a "library mode". A user would be able to stick a CD in the CD drive of a running server and have the thing automatically looked up on CDDB, ripped, and cover art downloaded. Users would be able to log in to the server and create playlists of the available albums. They could click on a "play" link in their webbrowser, and the server would begin streaming audio data from their playlist to their audio player.
The main difference from any other audio server is that this one would act as a "library", where each album is "checked out" by a user for as long as it is in use. Whoever starts playing an album first "locks" it. Any other users who have the album in their playlist will simply have that album skipped over. When the locking user has finished hearing the audio from the album, the server unlocks the album and acquires a new album from the server.
This is significant, because this is legal, even though it allows everyone to enjoy the music. Have a nice big box next to the server, and every time you rip a CD to the server, toss the CD in the box, and you have proof of legality.
The main fact that this takes advantage of is that most people don't care about strict inter-album ordering when playing music (as a matter of fact, some people play individual tracks on shuffle mode). In return, it provides a large music library very inexpensively. If each person at a 50 person company brought in a handful of CDs that they like listening to at work, a large and varied audio library is created.
* It might be desirable to label each ripped album with the contributor's name. That way, if the contributor ever wants their CD back, it could be handed back and the ripped audio easily purged en-masse ("delete all albums from user bob7").
* This could easily become a self-funding open-source project if it was a decent piece of software that included "buy this CD" links to a vendor that was willing to provide a cut of money for referral links. (If one really wanted to get fancy, one could provide direct "buy and download to server" links for iTunes and similar services.)
* This is a good example of a system where "phone-home" capability would allow a TiVo-like suggestion system.