Apple last week opened a San Francisco flagship store in the city's tony Union Square shopping district. The store has a 42-foot-tall sliding glass door and a 50-foot tall green wall and is powered by 100 percent renewable energy, the company said. "We have a deep commitment to the cities we work in and are aware of the importance that architecture plays in the community," said Jonathan Ive, Apple's chief design officer. "It all starts with the storefront ... where the building blends the inside and the outside."