Take a look at the Batuca cases as well. They are 1/2 the price of the CountyComms and provide much better dust/grit protection. Still, I have some extra-thick little zip bags that perfectly fit 4 CR123s or 6 AAAs. These are more waterproof than the CountyComm or Batucas, and you won't find anything more space efficient. I'll post a pic later if I can snap some photos.