This parking lot in Tampa has a quaint old "honor box" left over from the 1950s or so, in which you leave payment in the slot whose number corresponds to the one on the space you parked in.
It was originally constructed to take quarters, which is what clearly dates it back to an era when parking here probably only cost 50 cents. Now in the 21st century when parking here is three bucks, they've had to leave some elaborate instructions for the public. The sign instructs you to fold each dollar three times before forcing it into the tiny coin slot and using a key to ram it in. It's not quite an exact science - the dollar is still pretty damn difficult to wedge in there, even after some aggressive folding and flattening.
There's a guy who lingers around here handing out those sign-language cards with the phrase "I am deaf, please make a donation", hoping to pounce on people while they've got their wallet out. I declined his routine, and then after he turned away I felt bad about it and reflexively said "Hey, wait". Equally reflexively, he quickly turned around with a hopeful expression and said "hmmmmm?" - then caught himself too late.