I use this:
http://www.basspro.com/servlet/catalog.T...t=SearchResults

There are ample slots and pockets in the front and back covers, but the beauty of this case is the ring-bind clear plastic pouches. I have my stuff in the pouches (added a few pouches)according to the "level" of need: Short hike in civilization; Camping trip near emergency medical help; Wilderness/Major kit. The sections work in concert: the Camping section includes the Short Hike pouches... the Wilderness section includes the Camping Section and Short Hike section.
When I want to carry less than the full kit, I pull the pouches and slip them in a pocket or pack.