I'm in the market for a new bag to carry my gear and can't decide between a messenger style or a backpack style bag. It is going to be a heavy bag hence my indecision between a messenger bag or backpack. It will be carrying a 15" MBP, Nikon D80, 70-200mm, 18-70mm, 1 Flash, accessories and more equipment in the future. I've narrowed my choices down to Crumpler bags as I don't want it to scream camera gear or photographer but still be designed for that use. I'm looking at the Brazilian Dollar Bag and the Karachi Outpost. The bag will mainly be used in photojournalism, travel, sport and street photography. I've never owned a messenger bag so please notify me if some of my concerns are not a issue. My points for the messenger bags: Pros: Ability to access its contents without having to remove the bag or set it down. Style: In a urban environment it "blends in more" than a backpack. Cons: Not as easy to carry/run with? Traveling for extended periods of time it may get hard to carry due to not having enough shoulder/hip support. Could get in the way when shooting on the move. Can't carry a tripod. My points for a backpack: Pros: Added security in that it has to taken off to access the main compartment. This at the same time is it's greatest problem. Much easier to carry over a messenger bag. Cons: Can't access it on the move. Has to be taken off. Can make one stand out in a urban environment though it has good security. I'm hoping someone here has used a backpack and/or messenger back for photography and can tell me what they suggest and how using it is over a long period of time. Thanks.