Keep iTunes Updated With a Music Folder

The best way to keep your iTunes organized is to allow iTunes to copy everything to your music library, and then to delete the original file to save space. If you do not have enough space to do this, just burn your stuff to a disk, or copy it to an external hard drive, such as your iPod, and then just clear your iTunes library, and re-import everything from whatever it was you had copied everything to, this time allowing iTunes to organize everything.

via Lifehacker by Adam Pash on 12/5/07

Windows only: Monitor any folder on your PC and automatically add new music to iTunes with freeware application iTunes Folder Watch. Just point it to the folder you'd like to watch for new music and let it work its magic. iTunes Folder Watch monitors the folder (or folders) for new music (i.e., music that doesn't already exist in iTunes) and can add music either automatically or queue it for you to selectively choose songs you'd like to add to iTunes. I once described a command line method for the same thing, but iTunes Folder Watch is a much simpler and full-featured solution. iTunes Folder Watch is freeware, Windows only, requires .NET; it's currently in beta, so expect a few bugs. Thanks Galley!

iTunes Folder Watch