My mom picks up anything that can be recycled when she goes for her job in the morning, and then rinses it and puts it in the recycling bin at home.  If a class of students go walking, they can pick up garbage too.

My mom once got stopped by a cop because she was carrying a beer can.  She told the cop she had picked it up to bring home and recycle. The cop suggested she keep a bag in her pocket in case she find beer bottles and cans so that people don't think she's drinking in the street lol