I used to carry a fairly small bag - enough for my wallet, cellphone, car keys, office keys, house keys and a pen. However, over the years, I felt I simply needed more space for magazines, newpapers, hand sanitiser, sudoku and kakuro books, my laptop, my Swiss Army knife, cellophane tape, granola bars and various other knick knacks. I got myself a carryall. But then I realised that I never could find the smaller items in my bag and that I would probably give myself a hernia.
This is a very well-known problem with large bags, and there are bags that employ compartmentalising to solve this problem, but I find I often end up with not enough space for my big items and I can never remember where I leave certain items. Because I feel I badly need a new bag - one that is more ergonomic and offers better protection for the more fragile items - I began paying more attention to other people's bags. Here is one of the ones that I have seen several times, mostly on the backs on cyclists:

The creation of Swedish product designer Jonas Blanking, the
Boblbee Megalopolis Aero Spirit was made to meet his needs as a outdoorsman and urban dweller. From
svenskform, "Blanking found the model for his backpack shell in the boxes used by the air freight industry. They met his demands for low weight and durability. He studied [the] materials and connecting joints. The... shell is... manufactured in injection-molded, toughened ABS plastic and is joined to the soft textile harness by aluminum strips and screws."

From
Canadian Motorcycle Guide, the bag is "[e]quipped with various internal pockets and compartments for things like laptop computers, CD’s, and mobile phones, it can also accommodate items strapped to the outside, like roller blades or even a basketball." Additionally, "the Aero harness that is made of a new lycra mesh laminate to reduce heat build-up against the wearer’s back, Aero Top that provides maximum water protection and airflow behind the rider’s helmet, and Aero Ratchet Lock for secure locking of the lid." (from
Boblbee)
So what is it like to carry one?
According to
Ronn Moffatt, "[a]lthough the ABS plastic does add a little weight to the pack, the comfortable ergonomic design compensates well. I have worn my pack containing an SLR camera and other sundries for daylong rides, without feeling as though my arms were about to drop off at the shoulders when arriving at my destination. Using the waist belt relieves much of the downward pull, and the closure—that connects the shoulder harnesses across the chest—relieves the rearward pulling forces on the wearer’s shoulders. These two items together would work well on any backpack, but on the Boblbee it all seems to work better."