I carry two cameras on straps, one over each shoulder, with any spare lenses, batteries and cards in my jacket pockets. Absolutely no bags, photo belts, hoops, pouches or anything along those lines on my person. I stay light, mobile and (most importantly) slim enough to wander in and around groups of people without getting in anyone’s way.
solid 8 hours or more. I wear comfortable black dress shoes (or solid black tactical boots for outdoor events), black dress slacks, black polo shirt and a dressy black jacket. I wear a utility belt with business cards, memory cards, lens cleaning tools, and lots of extra batteries as well as my Canon flash battery pack to power my 580. I wear two cameras (which can get uncomfortable). Once body has the 70-200 2.8 IS and the other has the 17-55 2.8 IS. The camera bags stay in the car