I once found what I thought was a shell on a beach....only to discover it was a human tooth. GROSS.
I occasionally find forgotten money stashed in my coat or pant pockets, much to my delight.
Oh, and my coworker and I found $1500 dollars in the mail drop at work. The guy who lost it frantically called looking for it; we were honest and gave it back to him. He did give us $20 bucks each for being honest