Denise -
I bought an Arkel Tailrider as a good way to carry (and protect) my camera. I carry my little point & shoot camera in a fanny pack, and my SLR in the Tailrider. The Tailrider is an awesome bag, and it has a lot of space in it. You can see my thought process in deciding on this bag on this page of my Panniers, a trailer, both? article.

I stopped using a handlebar bag many years ago - I don't like the change it makes to the handling of my bike. Some people love them, guess I'm just one of the people who doesn't. I do use a Camelbak for extra water though - I keep Gatorade in my water bottles and water in my Camelbak. On hot days that's absolutely the right answer for me. Why are you ruling out a Camelbak? The one I use is the Rogue, which is pretty basic. That is, it's really meant for water and is not a full-blown backpack. There is room to stash a few things (like my car keys and some energy bars). And it's pretty narrow, so I find it quite comfortable.

--- Denise