This occurred before I was a cacher, but everytime I tell the story, people laugh:
I was at a local park with some friends for a picnic. We were under the pavilion, when a pickup pulled up on the parking lot. A young woman got out first, with her baby. "rough" looking male companion got out next and walked away from the truck. The woman laid the little guy in the back of the truck, changed his diaper ( we could smell it 20 feet away) and proceeded to drop it in the grass next to our pavilion. There were 3 trashcans closer than us. Then, she walked away, presumably to join ROugh on a hike. One friend said to us, "I dare somebody to pick that up." I wasn't married, and had no kids, but had changed plenty of diapers in my time anyway. So, I picked it up, opened the door to their truck ( they were dumb enough to leave it unlocked, so they deserved it ) and dropped it, dirty side down, on the seat. It was nice and hot that day, too, and the windows in the truck were up. The rest of our group waslaughing hysterically. Not to be outdone, my friend Chris grabbed a piece of scrap paper and wrote: "I think you accidentally dropped this" on the paper, opened the door, and put it on the diaper. Then, we waited.
There were several groups enjoying the park that day. they gave us a standing ovation when we sat back down. Hoping no one would squeal, we waited for the truck owner's return. ABout 30 minutes later, they came back. The look on Mr. Rough's face was priceless. We all heard the woman say, "I didn't put it in here! How stupid do you think I am? They started arguing and looked a bit lost. Chris sttod up, walked over, asked if everything was ok, real innocently. Then, she came over to us, grabbed some paper towels and gave them to the woman. I heard her say, "Sorry, we've been here all day but we didn't see anyone near your truck. the nerve of some people!"