The Timbuk2 brand of messenger bag was a concept designed by a messenger rider in San Fransisco to meet the needs of fellow messenger cyclists. And, since 1989 it has grown into an incredibly popular bag design that is used by cyclists and non-cyclists everywhere.
One of the neatest things about the Timbuk2 messenger bag is its durability. This is a bag that you could buy when you start college, and you could hand down to your grandson who is about to start college. It's handmade construction is truly one of a kind.
Even if you never ride a bike, its quality as a book bag is unmatched.
Secondly, it has a waterproof liner that does surprisingly well at keep the elements at bay. I have ridden in some pretty inclement weather before, and I am always amazed at how dry my contents are. If you are transporting a laptop or other electronics, you will probably want to use the yellow raincover to make sure the water stays out
There are a lot of Timbuk2 bag designs to choose from. I found their classic bag to be plenty large for a laptop and a couple of text books. If you need more room than that, well, they have bags for that, too.
Plus they've developed some fun new bags such as the Shift. The Shift will ride on your pannier racks, or can be used as a messenger bag for the ultimate convenience.
Frankly, I don't know how anyone can be a dedicated commuter without someway to carry their belongings. I love the Timbuk2 messenger bag with the freedom, flexibility and style it evokes.