The carbon Ram Laptop Backpack from Timbuk2 holds up to a 15" laptop in its own padded compartment. The main storage area can be used to carry your collateral material, water bottle or sneakers.
The bag provides three ways to carry it. First, it's a backpack with tuck-away straps. Second, the removable shoulder strap turns it into a sling-style messenger bag allowing you to swing the bag around to the front to access your gear. Third, its grab handle makes it useful briefcase-style. A rear trolley sleeve allows you to toss the pack over your optional rolling luggage cart.
The bag is made from ballistic and ripstop nylon. A zippered exterior pocket is for small accessories. The Ram also includes a bottle opener attached to an internal strap. Access to the bag is via two zippers that run the top length of the bag. The front protective flap is secured with two quick-release buckles.