I store all my video content on another drive that does not contain my music library and I want iTunes to copy files to my music folder most of the time. However, when I add videos, there's no sense in having the same video in 2 locations but, it's bothersome to go into iTunes prefs and turn off "Copy Files to iTunes Music Folder When Adding" each time I wanna add a video to iTunes but, not copy it. Tonight I found out that if you hold down the option key while dragging files into iTunes, it adds it without copying it to the Music folder! Nice!