The airport. It’s not a place where most people want to spend more time than is absolutely necessary. Stand in line, have your documents evaluated, walk around, repeat. Even fewer people would consider living there, even though most of them are already packed for it. But why? San Francisco International, like most big metro airports, has many of the same features as a city neighborhood – restaurants, shopping, museums, cranky neighbors, rail transportation and public art (and the renovated Terminal 3 is only slightly more gentrified than Valencia Street in the Mission District). And the cost of living there, apparently, is comparable to that of a San Francisco apartment.