Heard the old phrase "not worth the paper it's printed on"? Well, as it turns out, a variation of that is true. "Not worth the metal it's minted on" is true of some older US coinage. Coinflation has the full details.
This is a tip for those who might run where giant swarms of gnats sometimes loiter by the side of the road. This tip stems from a run on the Mayan Riviera in Mexico, but I've encountered swarms of gnats in Virginia and Kentucky as well. After your run, always stop and look in a mirror before going into public. Otherwise, you might actually complete a transaction at the resort store and greet five people before realizing you have up to 15 gnats stuck to your face and neck.