Cup or Mug libraries are becoming an everyday sight at responsible cafes across the world from New Zealand Canterbury University to Canada to the UK, Australia to Germany.
It is a really simple idea. Instead of using a disposable cup that cannot be reused, recycled or rot due to the plastic lining you can use a donated cup or mug. Once used return it the next time you visit the cafe. It works similarly to Boomerang Bags, and that is why I call them Boomerang cups.
Donate your unwanted clean cups to your local cafe.
If you forget your keepcup pick a boomerangcup from the cup library.
Bring the washed cup back to the cafe next time you visit.