If you have seen Grylls' Man Vs Wild series on Discovery Channel, you already know he has done some really krazy things. But, he really overdid himself in the Ireland Ipe trail, rappelling the cliff on a Kamikaze knot (knot also known as 'sheepshank'). People please don't try doing this, it is really dangerous.
Details of the knot:
http://answers.yahoo.com/question/index?qid=20080903201022AAoYSsK
More on knots:
http://www.summitpost.org/fact-sheet/189632/knots-for-hiking-and-climbing.html
