Discovery Channel's "Survivorman" Les Stroud wouldn't be caught dead without one and for good reason. The name says it all -- multi-tool. Swiss Army knives are the favorite of Boy Scouts everywhere, with their tiny saws, pokers and toothpicks. While the little red pocket knife can come in handy, it's no match for the modern multi-tool. There are many kinds, but the "Leatherman" multi-tool is probably the most widely recognized. They gained popularity in the 1980s, but since then the Leatherman and other multi-tools have come a long way with the myriad options to choose from.
Your standard multi-tool is comprised of two halves joined by a pair of pliers in the center. Depending on which one you opt for, you'll have a number of options. They typically weigh between 5 and 10 ounces (141 to 283 grams). Most will come with flat and Phillips head screwdrivers, pokers, saw blades, and bottle and can openers. Some models come with scissors, serrated knives, metal files and Allen wrenches. When it comes to aiding your survival chances, you should probably go with one that has the most knife blade options. Allen wrenches are nice in a workshop, but they won't help you filet a fish.