For years, one of the biggest complaints about iTunes has been its inability to automatically add new music to your library from a watched folder. As of yesterday's iTunes 9 release, that's no longer the case.
via lifehacker.com
So, no longer need to drag/drop or add to library, just put what you want in iTunes inside this folder and it goes into iTunes's Library automatically.
Apple's explanation: http://support.apple.com/kb/HT3832
