I had to read through TeeDee post a couple of times but I now see, with the help of Grizz's explanation, what he is doing and think it's going to be a great system to get a very consistent hang. I can't wait to get out and test the system. You really flatter me that I was part of the inspiration on putting this system together. I guess a blind squirrel will find a nut every once in a while.
As far as measuring distance between trees, you may take a look at the laser measuring devices sold at home improvement stores like Home Depot or Lowes. I have one that pretty light. They are made for measuring rooms or other items around the home. You but the butt end of the device against one end of what you are measuring and the unit fires a laser at whatever you are measuring a distance away. Accurate to within a couple of inches per 50' I believe. I use the hiking pole/outstretched arms to measure the distance between trees all the time, and it works well for getting a general idea if my hammock setup will fit.
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it."