This isn't what I found, it's what I lost. I left a 7 iron on a green at my home course. When I went into clubhouse the next day to ask if it had been turned in the kid behind the counter asked what club I was looking for. When I told him my 7 iron he replied, "Oh, I have one of them, I would have turned it in". So I assume that if he found a club that he did not have, he would keep it.
So guys that have lost anything on the course, consider yourself very lucky to ever get it back with people playing behind you with that kid's attitude.