Quick question, and I haven't found the exact answer via search. I am buying a new MBP and external HD. Not sure what HD I will buy, but I plan to put all my files from my iBook onto it and then have the ability for the MBP to see the files for when I want to use the photos or add the songs to my iTunes. Is that possible or will the HD need to be formatted for each computer? I am not familiar with external HD's so apologize if this is a simple question. I would prefer to back up everything from the iBook to the ext. HD rather than transfer everything to the MBP.