AOL Greenhouse Product Info for AIM Buddy Tunes: "Stream your iTunes music library to your buddies with AIM Buddy Tunes. This plugin for AIM 6 extends iTunes network streaming to your friends on your buddy list, so they can hear what great musical taste you have. Browse songs and playlists and just click play to listen."
I only use iTunes on my Mac (which this plug-in doesn't work for), but I know most of the rest of the world uses iTunes on their Windows machines. To get started make sure you turn on your sharing preference in iTunes. You can do that via the Edit menu in iTunes and choosing Preferences. Select the Sharing tab and make sure "Look for Shared Music" and "Share my library on my local network" are both checked. Download the plugin and run AIM 6.1 or AIM Lite. In the shared list you will see other buddies music libraries who have the plugin installed.
Note: Any Fairplay (DRM) protected content cannot be played unless the remote machine is authorized.
If you like it, hop on over to the developer's blog and let him know what you think.