Packing light for a weekend of camping doesn't mean you have to sacrifice the toughness of your gear. The Survco Credit Card Ax lives up to its name with a rectangle blade that features 21 functions, and measures just 3.6" by 2.1"—the same size as a credit card.
The arrow on the blade folds out and can be affixed to any handle with straps or rope. But it'll also replace other heavy tools in your stockpile. It's got several different sized wrenches, a bottle opener, seatbelt-cutter, plus it can function as a tomahawk, saw, and even a spear. Forged from 12-gauge stainless steel, this is easily the most valuable card you'll have in your wallet. [Amazon.com, $23]