My itunes library is getting a bit too big for my computer's hard drive. I'd like to put part of it on an external drive, but want to keep most of my music on my computer's HD. Say, by moving all my podcasts to the external, or moving all "unchecked" files to the external. Is this even remotely possible? If not, is it possible to create two "libraries", each on a different HD, and have them both load on to my ipod?