Have a Random Acts of Kindness day!
Buy a few bunches of flowers and (with a friend, to up the entertainment value) go to a grocery store or other large parking lot and discreetly put a flower on a few cars. The idea is to spread out the flowers so people don’t see them on any other cars. You can also stagger “delivering” them to the cars one at a time. Then, sit in your car (pretending to pay no attention to the people coming out to their cars) and watch what people do! This is highly rewarding and entertaining, though it could be an exercise in creepiness… because people are very suspicious. You could also include a note to the effect of “have a happy day” to lessen the freaky factor. Have fun…. : )