In November 2001 I had just migrated from BeOS to OS X and was sorely missing the ability of my MP3 player to broadcast my home collection to work (see iTunes Needs Streaming). All the hubbub surrounding the new iTunes music store has eclipsed the news that it’s finally possible to do exactly that. I’m sitting at work right now listening to my home MP3s, and haven’t dropped a frame in two hours. All 16,000 tracks are immediately available, with all the usual search functionality. All my playlists (both standard and “smart”) are available. I’m in hog heaven.
If you set sharing on in the prefs, you can also provide a direct link into any point in your collection — Cmd-Click and select Copy URL. philm points out that it’s also possible to link to specific items in the iTunes store. Check these examples.