Shaunacy Ferro wrote about a creative litter reduction campaign:

• If the act of throwing trash away can be made fun, rather than seen as a chore, fewer people would litter.
• A UK non-profit is attempting to do this by making the act of throwing away a cigarette butt a way to express one’s true allegiance.
• Smokers can choose between Ronaldo and Messi as the best player in the world, and passerby’s can see whose winning.
• Cigarette butts are specifically targeted because 89% of them are left on the street.
• No word on whether the campaign could inadvertently increase rates of smoking among die hard sports fans.

See another example, and read more here.

Source: Mental Floss