Think emergency bandage, water filter, fire starter, blow dart fletching, fishing bobber...
This does all that and more. It's available at any local pharmacy. It weighs mere ounces. And it rhymes with "crampon" but doesn't go on your feet.
And, according to the guys over at The Art of Manliness, it's worth throwing in that survival kit of yours. Read on here.
Have other tips on being resourceful in the backcountry? Share them with us.