One thing that photographers end up with a neverending closet full of is camera bags. It's like vain women and shoes. Never is any given bag the right one for a given situation, which is why we keep buying more. So the more resources that are out there to try to help a photographer find the right bag, the better.

I travel light. I don't pack every bit of photo gear I own in order to go on a photo shoot: a couple zooms is usually enough for me. So I find that I prefer waist bags: they don't require you to put down the bag to get anything out (unlike an awful lot of backpacks); and they don't cause pain on even short hikes (unlike shoulder bags). The disadvantage is limited capacity for photo gear, and I can't really figure out a way to carry things like lunch or inclement weather clothing with them--larger waist packs don't seem to play very nicely with daypacks.

My two waist bags are a Lowepro Off Trail 2 (which has been replaced by the Lowepro Outback 200) and the Think Tank Skin Chimp Cage (which has been replaced by the Think Tank Skin Body Bag).

The Lowepro Off Trail 2 has a central compartment which is capacious enough for a large DSLR and a large wide or standard zoom lens. In it, I keep my camera with a large lens mounted, with a small lens at the bottom of the bag. It also has slots for Lowepro's modular sliplock cases; it came with two long and skinny cases, each suitable for a longish but slow lens, or two small lenses separated by a padded divider, or a flash, or a standard water bottle. I bought two cases to use in place of these as needed; one a wider, shorter case for a fast, wide angle zoom, and the other a mesh bag which holds a 1 liter water bottle. I've successfully used this bag, swapping lenses on and off of my camera, while wading in Mono Lake. I've configured some carabiners in my car to carry this bag hanging off my passenger seat headrest. Keeps everything neat, see.

The Think Tank Skin Chimp Cage I bought for backpacking, where my bag space is by necessity primarily occupied by things that aren't related to photography. This bag is meant to go with Think Tank's modular system, but in the past I've just attached this bag to the waist belt of whatever backpack I'm wearing at the time. It's an unpadded case which is marketed to hold two small telephoto lenses or a single 1D or D3 class body. However, I've also coaxed it into holding my DSLR with a large zoom attached, and another zoom in the bag; or in another configuration, it comfortably holds my Olympus OM-1 with three lenses (28mm f/3.5, 50mm f/3.5 macro, 135mm f/2.8, one on the camera, two stacked by use of a pair of rear lens caps glued back-to-back). The Skin Chimp Cage has an integrated rain cover, which when folded up doubles as bottom padding, and it offers two accessory pockets which may be used for various items (filters, batteries, film, memory cards, lens wipes, etc.). Now I pair this bag with the Think Tank Thin Skin Belt, which permits me to wear the bag independently of the backpack--and take off the backpack without also taking off the waist bag.

Ultimately, both of these bags I use for specific situations, and they're not perfect. But they do a good job in general.