There are several other options as well depending on what you want. I use a element-proof Aloksak bag. It's basically a heavy-duty Zip-Loc. I wear my PSK in my front left cargo pants when i'm on search & rescue assignments or deep in the wilderness on fishing or hiking trips. I find myself going for it once in a while for quick and easy access to a small knife, a lighter (to fire up propane appliances), my Photon Freedom LED light, etc.

If you would like a hard but cheap container, also consider the Lock N' Lock plastic containers.