Josh Clark is a designer specializing in mobile design strategy and user experience. He's author of "Tapworthy: Designing Great iPhone Apps" (O'Reilly, 2010) and "Best iPhone Apps" (O'Reilly, 2009). Josh's outfit Global Moxie offers consulting services, training, and product invention workshops to help creative organizations build tapworthy mobile apps and effective websites. Before the internet swallowed him up, Josh was a management consultant at Monitor Group in Cambridge, Mass, and before that, a producer of national PBS programs at Boston's WGBH. He shared his three words of Russian with Mikhail Gorbachev, strolled the ranch with Nancy Reagan, hobnobbed with Rockefellers, and wrote trivia questions for a primetime game show. In 1996, he created the uberpopular "Couch-to-5K" (C25K) running program, which has helped millions of skeptical would-be exercisers take up jogging. (His motto is the same for fitness as it is for software user experience: no pain, no pain.)