The figure of eight knot is a very useful fellow in rescue work and outdoor related sports in general. There are eight variations of this knot and I will list them here.

The figure eight knot is a stopper knot when tied in a single rope and is used to prevent the end of the rope from going through something, like a grommet , pulley or some such thing. The Figure of 8 in a bight is used to create a loop in the end of a line or the middle of a line. This could be used to clip into the end of a rope or a karabiner could be snapped into it and it could be used to clip onto a load. The figure of 8 follow through is used when the end of the rope must pass around or through something that prevents you from just clipping in, with this knot a standard figure of 8 is tied into the rope and the working end of the rope is past around or through said object and then, the working end is fed through and follows around the original knot. The figure eight bend is used to tie two ropes together to double  the rope. The double figure 8 is used to create a double loop in the end of a line. These loops can be the same size or one may be larger than the other depending on what you are planning on doing. The in line figure eight is a directional knot meaning that there is both a left and a right version and this knot creates a loop anywhere in the line that can be clipped into. The figure 9 knot is classed as a figure eight as they are the same family of knots.  All the knots mentioned and how to tie them can be found on www.animatedknots.com a great knot resourse. I bought the DVD even through I could tie the knots I liked it that much.

Another good resourse is www.onrope1.com  Very helpful folk to be found there. Cheers, Greg