Small pieces of paper, to wrap your gum in if there is no bin within sight.
1
Cut out a piece of cardboard from food packaging or something, of 4x8 cm.
2
Cut out a stack of papers from magazines, or any scrap paper lying around, and cut them slightly smaller then the cardboard.
3
Use a staple to fasten them to the cardboard, and done! No more need to contribute to the ugly gum stains in the streets! :)
Easy Peasy :)