I just received my new MBP. I am having a hard time figuring out my external HD configurations. With my previous computer, my iMac, I had one external HD. It was only 160GB, but I used it to backup most of the documents from my internal HD. I also used the external HD to store my iTunes library. When playing music, it would always be played from the external. I figured there would be an advantage to using the external for constantly playing music, rather than having it competing with everything else on my internal. This was all on a machine with OS X 10.4, so time machine was out of the picture. Now, with the MBP, I want all of the info to be portable. I am considering storing my documents on the internal HD, while still having a small portable external HD for music. Is there any particular advantage to this? Or should I leave it all on the internal and just get one large external HD to use with Time Machine? Lastly, how does Time Machine use the disc? Does it just create a folder where the redundant info is stored? Can I store other information on it, or does it monopolize the disc? How do you other MBP owners' have your external HD's set up? Thanks in advance.