Take-a-penny, leave-a-penny jars are some of my favorite things. From a practical standpoint, they keep me from ending up with a load of unwanted change when my total is within a couple cents of an even dollar amount.
Impractically, they are the best version of generosity.
They are the place I can leave a couple pennies for someone else. A complete stranger who has nothing more in common with me than using cash at a specific establishment. Other than that, they will never know I existed. But they will reap the psychological relief and monetary benefit of a few cents left in a tiny cup for their moment of need.
Where can you leave an intentional benefit to someone else? How can you make a small donation to a strangers moment of need? What can you do to add value to someone in the midst of their daily mundane?