So, I have got a MacBook Pro with a 100GB hard drive, and want to make it my main computer. My current iTunes library weighs in at about 65GB, which will take up most of the usable space on the internal hard drive. I would like to create a setup with two iTunes libraries. A small ~15GB one with "most requested" songs will reside on the internal drive for listening on the go. The "main" 65GB library will be on an external hard drive at home. The trick is, I want the switch between the libraries to be either automatic, or very quick and easy. Did anyone here make a setup like that work? Any tips?