Jake Ludington points to a nice plugin for Windows Media Player that lets you share Windows Media libraries among computers on a LAN. This function duplicates what iTunes users have always enjoyed. On2Share runs on all computers on the network and shares the media library among all configured PCs. The utility is freeware and can be configured to automatically add libraries for all computers on the network. Nice stuff. From Jake:
In theory, by installing On2Share on all the computers in your home, you can find the library of each machine and automatically create additional playlists with files listed on those machines. This works as long as you keep Windows Media Player open on all your machines all the time. If you close Windows Media Player on one PC, other PCs in the house no longer have access to the music and movies on that computer.