LifeStraw
If you've ever watched Naked and Afraid, Survivorman, or anything starring Bear Grylls, you likely know that one of the first things you need when you're out in the wilderness is fresh water. And while you can certainly carry a stove and pot for boiling water along with you, why bother when you could just pack along a LifeStraw? This award-winning personal water filter removes a minimum of 99.9999% of waterborne bacteria and 99.9% of parasites, is good for up to 1000 liters, and lets you drink right from the stream, lake, or river, without worrying about having to call for a medical evac.