The Yakpak medium tech flapdoozy is the middle child in a line of messenger style bags. While it is not exactly the largest bag they make, it is perfect for holding the gear I need it to -- specificially my IBM Thinkpad X22, Cell phone, and a notebook or two for classes.
The outside flap is secured with a set of four velcro patches in addition to a clip. This flap also has a zippered pocket, ideal for holding stuff like a wallet, checkbook, random slips of paper, etc (I tend to hold that stuff in the inside pockets though). Inside the bag there is (of course) the main compartment, with a small pocket towards the person-side of the inside. On the front end, there are two small unzippered pockets, with a larger zippered one behind them. Oddly enough, these pockets are on their own independent flap-like piece of material, and it can be flipped out such that it sits on top of the velcro straps and leaves a little more room in the main compartment. For those mass transit travelers among us, there is a card-shaped holder on the outside of the bag, ideal for holding ID or a bus pass.
The strap of the bag is rather long, the way I tend to them, and the bag sits comfortably at my right hip with the strap extended to its full length. On the rear side of the bag, at the base of the strap, Yakpak has sewn on a cell phone holder made of an elastic material. It holds my Samsung phone rather well.
As far as component materials go, its made of a durable canvas-like fabric that seems to be holding up well to my beating on it. I take my Thinkpad everywhere with me, so I'll soon be able to see how the bag holds up to heavy use.