The other day, I left a couple apples on the wall in the alley behind my apartment. I didn't want them but I thought maybe one of the homeless people who frequent the alley would. I noticed a few residences down, someone had left a bottle of water on the wall too.

The next morning, when I was walking to my car behind my apartment, I saw this.

There was another where the bottle of water was left too.

That's the nicest "thank you" I can imagine.