I have a Macbook Air with only 80gb of disk space. After installing different applications I'm really left with not much space left, so anything more is helpful. I have an iPod classic 80gb. After I add videos and music to my iTunes, I delete the actual files to save space on my laptop. My question is, how can I go about saving space on my laptop from iTunes taking up so much space without deleting my media? Is it possible to run iTunes on my portable HDD?