I came across this gadget last night. Looks like it would work really well
Let me start by telling you the story of two Johns.
John number one went on a day hike with a couple of friends in the Cascade Mountains about an hour from Seattle. He somehow got separated from his buddies and became lost. John was dressed in casual cloths for a warm weather day hike and had nothing but a lunch with him. He spent three days in those mountains and luckily made it out to tell the story.
John number two, a friend of John number one, was much better prepared when...