Since this thread got bumped, figured I might as well add that I got the Tracy Job Kristen bag for Christmas (per Susan aka Chikabowa's recommendation earlier in the thread) and so far, I love it.
It's big enough right now to hold my D60 body with the 18-200mm vr lens on it, the 50mm f/1.8, the 60mm f/2.8 micro, the 18-55 kit lens, the SB600 flash and some memory cards/my gorillapod/cleaning pen. With all that loaded in and worn as a messenger bag, it's really comfortable. Doesn't dig into my shoulder at all and still has plenty of extra room to toss in a water bottle or a Passporter, etc. While I haven't taken it out for a full day of shooting yet (I probably won't get around to that until the end of March because of the stinky NJ winter), I do bring it to work with me everyday in case I feel like walking around shooting on lunch.
Definitely for the price and comfort, I would give this bag 1.5 thumbs up, the only thing that might make it two would be if it was made of some sort of water resistant/proof material so I wouldn't have to worry about using it if it was starting to drizzle while I was out, etc. As it is right now, it's made from what seems to be cotton...so it'll be sopping up any precipitation that may land on it.