Here is the link to the one I like the best:
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=004717#000000 Most of the pics have been deleted. Look about halfway down page one to see the finished product and use this pic as a reference. It is very simple.
Parts needed:
1. 34" of 1" wide nylon webbing (REI)
2. Grommet kit(I bought the 3/8" kit and they were too big) (home depot)
3. Parachute cord or rope
Instructions:
Fold the webbing in half and sew the folded over end about 1 1/4" from the end (this forms a small loop at the folded over end).
Pass the two loose ends through the sewn in loop.
Install a grommet in the ends of the two loose ends. One grommet through both pieces of nylon webbing.
Run both ends of the parachute cord through the grommets and knot. Make sure the knots are big enough that they will not slip through the grommets under tension. This way is more adjustable if more than 1 person might be using it. You can also tie it like in the picture in the above referenced thread for a more secure attachment.
You are now done.
Bisch