Rating: - Great for travel
I share pretty much all of the same opinions with the other reviewer. I also removed one of the velcro dividers in order to use the bag with my Canon S3 IS and adaptor/lens converter. I keep batteries and memory cards in the front pocket, a card reader in the side, and a lens cleaning cloth in the flap pocket. With some wrestling, I can fit my large AA battery charger in the bottom of the main compartment, but I don't think I'll do this unless necessary.
Buy this bag if you like to carry lots of accessories with your camera. Do NOT buy this bag if you are just looking to carry your S1/S2/S3/S5 IS and a few small items (like a set of batts and a memory card). This will be WAY too big if that's the case. An alternate, smaller bag I recommend is the Lowepro Edit 110 mini-camcorder bag. That worked well for my S3 IS and its batteries and cards, before I got the extra lens kit.
Rating: - Digital essentials only
I got the 3535 Ultra-Compact Messenger Bag to carry my Canon S3 IS, extra batteries and memory cards and a battery charger. The camera has a lens adapter + filter + new cap, meaning its depth has grown. In order for it to fit in the bag, I had to remove one of the padded dividers (a horrendous battle with pieces of velcro sticking to everything), but now the camera fits nicely, lens turned upward. The remaining divider separates the camera from the charger, which is good. Extra batteries and cards are safely stowed in the front compartment -- the cards within the zippered part. A cleaning cloth fits in the small compartment on the front flap. There is a little side pocket for my cellphone, a nice touch if I don't want to carry extra volumes on a day out. The bag is well made and very sturdy, padding on all sides. I would like it to be slightly shorter and slightly wider, but it does the job well.