Search for one of LennyCorn's posts with all the links he has. There is a link to a piece of free software that will measure your snake for you based on a picture. All you do is take an overhead picture of your snake next to or on top of something with a fixed, known length. Input he length of the base measurement, then "track" the lngth of your snake with series of mouse clicks, and it calculates the length of your snake. It is reasonably accurate.