All some people want from a GPS is the ability to get back to the rig. They may be knowledgeable about wilderness survival and carry a survival kit, but they aren’t into geocaching, aren’t particularly concerned about where they are at all times and don’t care how many waypoints the receiver will store.
"Here's my definition: Survival is the ability and desire to stay alive, all alone, under adverse conditions, until rescued. Survival is an attitude." - Peter Kummerfeldt
Trash bags are included in all my survival kits. They have a multitude of uses, including being containers for picking up trash! But in an emergency, when correctly used, trash bags can prove a quick, temporary shelter from the elements.
TV survival shows to the contrary, it is virtually impossible to make a waterproof shelter out of natural materials, even if you have the time, tools and practice! Even with a tarp, you must have some idea or plan on how to fashion a refuge from the elements