My Pentax Optio S4i in its factory dive housing is smaller than many cameras even before they're put in a housing, so it fits right inside my BC pocket. That way I take it on every dive, whether I'm planning to use it or not!
I do have one of those coil lanyard thingies connected to the D-ring just above the pocket. I zip the pocket all the way up to the coil, which extends down into the pocket to connect to the camera.
If I deploy the camera underwater, I pack it back into the BC pocket during my safety stop (what else are ya gonna do just hanging there?).
This way, I don't need anyone's help to handle my camera... but the downsides are the Pentax sacrifices quality for compactness, and I can't use a nice strobe and still get away with stashing my camera in this manner. But for now it's worth it to ALWAYS have my camera with me!
>*< Fritz