Volkswagen has hit the viral nail on the head with "The Fun Theory," a series of short videos that make the mundane — such as using the stairs — oh so much fun. Produced by DDB Stockholm, the videos have been a hit on YouTube and are complimented by TheFunTheory.com, a platform for user-submitted ideas that are voted on by a panel of celebrity judges. It's tenuously related to Volkswagen at best, but the goodwill spread by it is probably worth its weight in gold.

View - "The Fun Theory: Volkswagen Masters the Viral Video" at Mashable