I've got an emergency bivy sack; tiny headlamp; firestarting tinder in a waterproof bag; a first aid kit in a waterproof bag; a lighter; waterproof matches in a waterproof container; super glue; a multi-tool with pliers, knife, and scissors; pain pills; whistle; compass; duct tape around a pencil; signal mirror; chlorine dioxide water-treatment pills; and a waterproof stuff sack to hold it all together.
I actually have two possibilities bags, tailored for different seasons and activities. Here's my summer one (right) packed and posing atop the North Hills behind my home.
One of my jobs for this review was to shoot some product shots, which I don't do often. But it was kind of fun trying to figure out how to capture this Leatherman in a complete and visually interesting way. After some experimentation, I ended up hauling a broken ponderosa pine branch into the middle of an open field where I could prop the tool and set it against the brilliant blue of the morning sky.
If you just want to buy a pre-made micro-survival kit, the Adventure Medical Kits Pocket Survival Pak (right) is the best I found. It packs a ridiculous amount of really useful stuff into a four-ounce package the size of a billfold.
To wrap up this journey into things that can help you not die in the woods, I'd like to show my man Jeff Boatman's meticulously awesome possibilities bag. Jeff is a pretty savvy backcountry character who makes a lot of his own gear (like the stuff sack in this picture). If something bad happened in the mountains, he'd be good person to have on your team.
Check out his exploded kit: