Here's an interesting article taken from CNN.com...
MOAB, Utah (AP) -- A Colorado climber amputated his own arm Thursday, five days after becoming pinned by a boulder, and he was hiking to safety when he was spotted by searchers, authorities said.
Aron Ralston, 27, of Aspen, was in serious condition late Thursday at a hospital in Grand Junction, Colorado.
Ralston was climbing Saturday in Blue John Canyon, adjacent to Canyonlands National Park in far southwestern Utah, when a 200-pound boulder fell on him, pinning his right arm, authorities said.
He ran out of water on Tuesday and on Thursday morning, he decided that his survival required drastic action.
Using his pocketknife, he amputated his arm below the elbow and applied a tourniquet and administered first aid.
He then rigged anchors, fixed a rope and rappelled to the canyon floor.
He hiked downstream and was spotted about 3 p.m. by a Utah Public Safety Helicopter. The search for Ralston had begun the same morning, after authorities were notified he was four days overdue reporting for work.
Ralston was described by authorities as an avid outdoorsman in exceptional physical condition. They said he was known to have climbed 49 of Colorado's major peaks. http://www.cnn.com/2003/US/Central/05/02/climber.amputation.ap/index.html