Found this cool Thread Identifier over at a site called LEE VALLEY & VERITAS (even their name is cool!) They describe it so well that I am just going to repost it straight from them:
"The Thread I.D. has a plate tapped for 10 National Coarse sizes (1-64 to 1/4-20), 10 National Fine sizes (1-72 to 1/4-28) and 8 Metric Coarse sizes from M1.6 to M6.0. Each type is color coded for easy I.D.
It comes with knurled-head bolts in all 28 sizes. This means you can identify the thread of any tapped hole in the range simply by using these bolts to find the exact thread size.
This feature is invaluable when a bolt has been lost and the only way to determine thread is to identify the thread of the tapped hole in the item it came from. It also identifies nuts; you just flip the tapped plate over and find the matching thread on the protruding bolts.
All of this comes in a fitted wooden box to ensure accidents won't damage the thread stock.
Patented. Limited stock."
The only problem with it is that they don't have any more for us!!!!
If the Lee Valley people see this, please make more.