I've finally found a way to setup iTunes to share write access to a single library.
I maintain a single integrated iTunes library for my family. However, everyone wants to maintain and edit their own playlists. iTunes' built in sharing allows you to play from a single library, but does nothing to allow you to edit that single library remotely.
I recently moved my entire library to my NAS and, inspired by a recent lifehacker post, I setup all the iTunes applications installed in my house to use the shared music and iTunes Library (.itl) share.
My steps were pretty simple:
1. Map network share on all computers to M:\
2. Move entire MP3 library to M:\Music
3. Copy iTunes files from My Music to M:\Music
4. Hold down the shift key while iTunes loads
5. Select the .itl file I copied to M:\Music
6. I had to go toe Edit/Preferences/Advanced and change the iTunes Music File Location from M:\Music\iTunes Music to just M:\Music.
Now I can control my iTunes Library from any machine as a 'first class citizen'. LifeHacker seems to be a pretty cool site that I guess I need to add to my RSS reader.