I had a PC laptop that was going out on me, so I backed all of my important documents (mainly my entire music library 30gb in mp3 format) onto my Western Digital external HD. It was formatted for PC. I plan on buying a MBP today or tomorrow and I am afraid that I'll have to format my external HD to a MAC and in the process erase everything being stored on it right now. Any suggestions or corrections to my thinking? Thanks.