David Hacin, AIA, knows everyone. The 44-year-old architect can't walk through Boston's South End, where he lives and works, without a stream of greetings from shopkeepers, neighbors, and fellow dog owners. Even in the city's other neighborhoods, he regularly runs into friends and acquaintances, often from the close-knit local design community. “I grew up in a small town,” he says, by way of explanation. “There's something [I like] about knowing the lay of the land.” More