This credit card-sized multi-tool ($20) turns screws, but, even more importantly, comes with a sharp edge that converts it into an axe for backwoods survival needs.
Simply find a sturdy stick, then use a length of paracord (not included), some zip ties, or even your shoelaces to strap the tool on and start hacking away at logs for shelter or a blazing fire. Will it work well? Probably not. But it's better than nothing in a pinch. And hey, it looks fun to play with. Made of 12-gauge stainless steel, it’s designed to take a beating.