Our United States Postal Service has one of the coolest things available for the August 21st Total Solar Eclipse. Their Total Eclipse of the Sun Forever Stamp uses the heat of your fingertip to change images.

In a statement from USPS: 'This is the first U.S. stamp to use thermochromic ink, which reacts to the heat of your touch. Placing your finger over the black disc on the stamp causes the ink to change from black to clear to reveal an underlying image of the moon. The image reverts back to the black disc once it cools.'

This is completely awesome, and perfect for the science nerd in all of us. The stamps are available now to purchase, so don't miss out, y'all!