The last messenger bag you'll ever need

I've been using my medium timbuk2 messenger bag for the past 2 years. Frankly, I think large is way too big. Even medium is a bit much for my 5'3" frame. Let me give you an idea of how much a medium bag can hold: 2 thick textbooks, a 15" laptop in casing, lunch, portable mug/water bottle, gym clothes + sneakers. So in short, it's perfect for those who leave early in the morning and don't get home until the evening. It has enough various-sized pockets on the inside and outside of the bag to feed all my compulsive needs. It works also exceptionally well as a carry-on and overnight or weekend trips. The bag is certainly durable and stylish with an added bonus of having the option to customize the color blocks. I liked that about timbuk2 bags -- crumpler bags seemed a little boring. And to clarify, timbuk2 bags are waterproof in a sense that the contents of your bag will not get wet; but the bag will, because it is the inner lining of the bag that is waterproof, not the outer material. Once the bag dries, it's as good as new, but I now spray my bag with a water-repellent from time to time.If you decide to buy a medium or large, definitely shell out a few more bucks for a padded strap, because while the strap is nice and wide, it provides zero cushioning for your shoulders.