Aron Ralston surely must be the symbol of our times. He's the ultimate survivor, a self-sufficient, super-rational adventurer prepared to adapt to any outrageous turn of fortune. You've probably heard of this remarkable mountaineer by now. He's the Aspen, Colo., hiker who amputated his own right arm with a pocket knife after it was trapped by an 800-pound boulder during a solo canyoneering expedition in a remote Utah desert. Pinned for five days and out of both water and ideas on how to lever himself out of the mess, the onetime Intel engineer fashioned a tourniquet with one hand, sawed through the limb without anesthetic, then rappelled down a cliff and hiked seven miles out of the ravine through a river before finding help. A few months before, he'd barely survived an avalanche while backcountry skiing.