I've had the desert sage Bail Out Bag for a while now, replacing an earlier generation model in black. (Trying to get away from super secret squirrel gear!)
I've gone back and forth with a Duluth Trading messenger bag, an old Eagle Creek convertible backpack-briefcase, and the County Comm BOB. Especially with warm weather, the BOB wins hands down.
It is great for a nature walk or picnic by the lake or day hike, with all those outside pockets for binoculars, camera, SAK, water bottle ... never having to dig in the bottom of a big bag for small gear. And it always seems to have room for one more piece of gear inside.