I can't help but notice that most of the small survival kits I see don't focus much on the shelter component. I was surprised to see that this kit did include a poncho. Cool! In my view lack of shelter and exposure to the environment is what kills most people.

Cody Lundin recommends three different kinds of shelter (light space blanket, heavy duty space blanket, and 55 gallon drum liners), but I'm guessing others use extended ponchos, small tents, or tarps.

I've also been thinking about the value of at least a small piece of closed-cell foam to provide insulation while sitting/lying on the ground. Of course that wouldn't fit inside the bottle. In a short-term survival situation, what would be used to keep the group from sucking heat away from you while sitting or laying down? It seems leaves are usually wet underneath (except for freshly fallen leaves) and won't really provide much insulation from the ground, especially with body weight on them.

For the bottle kit, you could also consider a bandanna, floss, a non-lubed condom, a small length of survey tape, 3' surgical tube for accessing water & other uses, waterproof paper/pen/pencil (do they make a small Sharpie?? - very good for writting on survey tape), a few safety pins, a large-holed needle, a few zip-ties, maybe an extra light-weight carabiner clipped to the loop (I prefer to have two of them for making shelter and other uses), maybe a fresnel lens (?).

Maybe you should carry two bottles??????