If you think the best multi-tool for the great outdoors has to have a corkscrew on it—think again. Mac Observer Contributing Editor and TrailCamper.com Publisher Chuck La Tournous is back for a fun, fast-paced, updated look at the gadgets that can turn you into a cross between Bear Grylls and MacGyver. Turn your iPhone into a full-featured GPS receiver, a homing beacon, survival guide and more. Purify water with a beam of light, charge your gear with the sun, fire — even with water!