I've got the urge to spend some money and the new gen4 20gig Ipods has caught my eye. I've started going to gym on a regular basis, but I don't have any sort of portage music player, so I think the Ipod would fill that gap nicely. Also, I had some plane flights coming up, and I think it would be nice to have something to listen to instead of simply staring out the window at nothingness. How decently does the Ipod double as a external hard drive? I got a 12'' PB and a PC so I'd like to be able to use it on both, is that possible? Please, convince me to buy one of these beauties. I should be able to pick one up today at my campus bookstore for the discounted educational pricing. Thanks!