The winner of the Starbucks-sponsored BetaCup Paper Cup challenge, Karma Cup, promotes the saying "what goes around comes around" very positively.
Every time a customer of Starbucks brings a re-usable cup with them, they cross an X on a chalkboard in front of the cash register. Every tenth customer with a reusable cup receives a free drink. Conceptualised by Mira Holley, Nick Patridge, Gillian Langor, Mira Lynn, Zarla Ludin and Ruth Prentice, Karma Cup is a great way to cut down on coffee cup waste. Check out the winning entry in the gallery, along with some other interesting entries.