These are all over the web, but maybe you never thought of using one
in woodworking:

http://www.ceismc.gatech.edu/bp/images/ruler.pdf

(looks funny in the browser, but works fine after printing)

download and print off a few on regular paper on your best print
resolution. In conjuction with spray adhesive, they are great for
measuring inside curves (for the calculus deficient), or anytime you
need a VERY thin measuring device on a flat surface.