Coin Ridges
Have you ever noticed the rough edges in dimes and quarters? This feature comes from the time when coins had different weights to reflect their value. People used to shave the edges of the coin to make counterfeits, so they added this feature as a security measure.
Grocery Cart Loops
If you were had to buy a lot of stuff at the supermarket, you should know that you can use the loops that frame the fold-out portion of the cart! You can hang the more vulnerable items there to avoid crushing them.