Hi, I recently bought a 13" Macbook Pro, and I'm looking to buy a bag to carry it around in. Unfortunately most of the bags I've seen are more like envelopes, just big enough to wrap around the computer and not carry anything else. Ideally, I'd like something a bit bigger than that, so that I can store the Macbook Pro and still have room for a book or two, some files, etc. Does anyone have some suggestions for bags like that? I'd really appreciate any help. Thanks.