Lightweight survival kits are generally seen as a backup means of survival; however, these can kits can be extensive, and have come to include tools that are generally found in larger kits as survival technology advances. Some examples of these tools are high power flashlights, rapid use saws, signal devices such as mini signal mirrors, and water purification methods.
The U.S. Department of Homeland Security (DHS) in their "If You See Something, Say Something" campaign says that "the public should report only suspicious behavior and situations...rather than beliefs, thoughts, ideas, expressions, associations, or speech...". However, it is alleged that a DHS list of the characteristics of potential domestic terrorists used in law enforcement training includes "Survivalist literature (fictional books such as Patriots and One Second After are mentioned by name)", "Self-sufficiency (stockpiling food, ammo, hand tools, medical supplies)", and "Fear of economic collapse (buying gold and barter items)".
Preparing for catastrophic or short range survival is extremely personal and most of us keep it tight to our chest. I think PowderKeg says it best – Invisible and then Nuttus who knows that not all of us are the same skill or wherewithal stage, yet as a TEAM we shore up each others weaknesses, learn off each others strengths and it is a continual building process going forward.
In arctic or alpine areas, survival kits may have additional cold weather clothing (winter hats and gloves), sleeping bags, chemical "hand warmer" packets, sun glasses/snow goggles, snowshoes, a collapsible shovel, a snare wire for small animals, a frying pan, a camp stove, camp stove fuel, a space blanket, matches, a whistle, a compass, tinder, medical equipment, a flint strike, a wire saw, extra socks and a tent designed for arctic use.
No one thinks they’re going to be trapped by whiteout conditions or separated from their group as night falls but it happens with alarming regularity. Don’t make things worse by being unprepared. These advanced Mylar emergency blankets cost less than 4 bucks each and weigh virtually nothing and yet can and do save lives. They’re waterproof, tear-resistant survival gear that comes in a pack of 5. As such there’s no excuse for not having them tucked away in your backpack or daypack when you set out. The very definition of essential survival gear for outdoorsmen of all stripes.