For about two months I would ride home and see a late '70s All Pro 3-speed leaning against a street sign, unlocked, never moving. After a couple of weeks of seeing it there, I stopped and took a look. Written on masking tape on the top tube was the word "free".
I debated about dragging it home every day as I went by. Finally last week it disappeared.
I can only imagine how much that "free" bike would have cost me had I succombed to the urge.