Although some posts allude to this, I think it's the first mention of sharing an iTunes library between multiple users on the same machine.

I'm encoding my entire CD collection so that my wife and I can fully utilize our iPod. However, with multiple users in OSX, iTunes naturally will create a separate library for each user. Not great when we're both adding new files regularly and need access to the most current roster of available MP3s. It's pretty simple use of aliases to solve the problem:

1. Logged in as either user, move the iTunes folder from the Documents folder into the Shared user folder.
   
2. Delete the same Documents/iTunes folder from each individual user.
   
3. Create an alias of this iTunes folder on Shared (remove the word 'alias').
   
4. Copy that back to each user's Documents folder so each user has an alias to the Shared/iTunes folder.
   
5. Your MP3 files should also be placed in the Shared folder. When you move them, you'll also need to "reset" the index of files in iTunes. Since you've set up everyone to work off ONE library, though, you only need to do it once.

This process will ensure that every user has access to the same list of files, regardless of who adds new rips. We also have an "Unfiled Rips" folder on Shared so we know what's been ripped recently, then file it alphabetically in the master pile 'o MP3s.

[Editor's note: Until I can convince her otherwise, my wife's primary machine is a PC, so I don't have to worry about this situation. We did, however, use Samba to make the MP3 directory on the Mac visible to her PC so that she'll have access to the same library of songs. I, however, am stuck with all the encoding work for now! ;-)]