All my music is on my Mac. All Arlene’s music is on her Mac. I wanted to be able to stream both computers’ iTunes libraries to the Xbox 360, but– wouldn’t you know it? the 360 doesn’t support Apple’s iTunes protocol, and iTunes doesn’t support the Windows Media Connect (WMC) protocol.
My first thought was to use Virtual PC with an XP Professional image; install WMC, use Virtual PC’s “shared folder” feature, and point WMC at it. However, as I learned from wmcplayer.com, WMC requires that the Network Service pseudo-account have access to the shared folder. Apparently, Virtual PC applies some other ACL to the shared folder, so WMC wouldn’t share music from the shared folder.
Attempt #2 was more successful: I moved my iTunes music library to superman, my Windows Server 2003 file server, and pointed an alias in my Music folder to it. Then I told WMC to share \\superman\music, and boom! I was in business. I’m not sure how well this will work long-term, because I bet iTunes will dislike living on an SMB volume. For now, though, it’s great to be able to listen to my (non-DRM’d) music on the Xbox.
Paul's Down-Home Page 
Hey Paul–
In the month or two since you did all the legwork mentioned above (well done, by the way), Nullriver has released a shareware plugin for Mac that replaces Window’s Media Connect. It’s called Connect360– it works flawlessly (with the exception of DRM tracks), and enables one to stream both iPhoto and iTunes libraries from Mac to a 360. You should definitely check it out!
Thanks for the suggestion, Ed– I bought Connect360 about six weeks ago (right before 1.5 came out) and have generally been happy with it. It uses a lot of virtual memory, and sometimes it stops streaming audio, but overall it’s a big improvement over my previous setup.