On Sun, 03 Aug 2008 18:44:26 -0500, Rick Morel
wrote:

There is a tuning tool available, but it's just a sort of spring
loaded thing with a ruler. A human thumb and ruler is a lot cheaper
and works just as well.

Read once you should measure and memorize your body parts and you can
become a walking ruler, no need to carry one.
Stick to stuff like fingers, finger joints, wrist bone to elbow bone,
etc. You don't want to get arrested while taking measures.

--Vic