My boyfriend was once in the dentist's office getting work done when he got a phone call there. It was a guy who found his wallet in a cab. BF hadn't yet noticed it was missing. Luckily the appointment card was in there, and he got his wallet back.

I also once found a wallet by a pay phone, and went to the address on the driver's license, and returned the wallet to the owner. The guy was really happy to get it back.