I've had a Timbuk2 messenger bag for about 15 years. Super handy bag, especially on a bicycle or motorcycle. With the strapping system, it is easy to snug it down without impinging on movement. It has served many purposes, and is currently my gym bag. It holds running shoes, clothes, extra socks and shirt in addition to my lunch, Sigg liter bottle and few extras.
Only problem with the old bag is it's too big for non-gym days. When full, it carries well, but nearly empty, it wraps around pretty far and is a little bit awkward.
When Mike LotS started a messenger bag thread, I started looking around the Timbuk2 website. Before long, I hadda get a smaller bag for non-gym days.

From the outside, it looks about the same size.

The inside shows the difference.
For reference, my size 9 Adidas running shoes are placed in each


In order to fit in the smaller bag, they had to be stacked one on the other.
The new bag is carried the same way, but has the advantage that even empty, it sits nicely on my back rather than wrapping sloppily around.
The new bag is waterproof, as is the old bag, but has a different system of waterproofing. Nice internal pockets and a couple outside pockets, very similar to the old bag.
All in all, a very nice daily use bag.
