Here's a fun concept from the Mexico-based Internet provider, Terra. The goal of the project is to encourage dog owners to do their civic duty (get it, duty?) by picking up after their dogs, thereby making the park a better place for everyone. To facillitate this, every time someone places a bag of dog poo into a specially marked container several free minutes of public wifi are added to a queue based on the weight of the poo.
As a result, the park is cleaner and people are free to go back to basking in the glow of their tiny handheld screens as they zombie-walk poo-free through the great outdoors. I just love a happy ending.