I'm ordering a MBP today (hooray Penryn!) but I'm wondering if I'll have to be as careful with it as I currently am with my Powerbook G4. I've never put it into a backpack, as I carry a large number of books and I'm afraid the weight of the books will damage the screen. I've basically been forced to carry it in an entirely separate bag, and this gets inconvenient. More so now that I intend to bicycle to work. Are there products for sale, relatively inexpensively, that provide crush protection for a 15" MBP? Ideally, it'd be a hard sleeve that stays in the bag while the machine is in use, but anything suitable (such as an "airline case") should work. All I've ever seen for sale are soft sleeves that provide protection against dropping, but nothing against crushing. Thanks in advance for your advice.