My DH and I do stuff like this all the time. A couple years ago I decided that every time I would go into any store that had carts in the lot I would at least take 1 in with me and 2 if possible. Then on the way out I try to leave my cart inside the store. I also try and pick up at least 1 piece of garbage in the lot on my way in. It breaks my heart to see the trash all over our beautiful land and see people ignore it. The prevailing theme with most things is: "It's not my job!", when in reality it is Everybody's job!