To avoid having this problem during the holidays, I was looking for a versatile bag that makes "wallet" + "camera bag", remaining a shoulder bag.
This Passport Sling answer perfectly to my request.
I used it all holiday for toting the usual contents of my wallet and my camera gear (EOS 60D, objectives 50mm f / 1.8 and 28mm f / 1.8).
The Canon and spend just 2 goals in the padded part (it must also do so with a larger COs hair).
The remaining part houses the remains easy, even a sweater over when we "deploy" the zipper part.
I was using the side pockets to jam my cap, and the pocket "before" welcomes my sunglasses when not on my nose.
Access to nickel bag, the bag is very light vacuum, which means that even with a good kilo photo gear, it does not feel embarrassed. Access is very easy in all cases.
(Even with a baby carrier bag on your back for long walks, I kept the bag rather than the device stuck somewhere or other)
Before ordering, I have been taking a look store. It is visually quite bulky, but its shape matching the body, you feel smaller once wore.
This bag is great, I think it will become my daily bag, allowing me to always have my DSLR with me.
The only "low" is that it is not "All Weather", but I think with a stroke of waterproofing spray, it must enable it to easily withstand normal rain.
(Meanwhile, in case of coarse, I folded freezer bag that will serve me to make a protective cocoon for my gear, inside the bag.)