I just got this from Jeremy Schmitt. He shows how to use the camera on an iphone to get measurements of tiny things (like my IQ?):
Sounds interesting, Dan. Thanks.If you (me) don't have a smartphone, all is not lost in the precise measuring dept!
Look at the huge number of USB microscopes now available. A LOT of them under $50! Some under $25.
The decent ones seem to have measuring capability built right in.