Pho Saigon's space -- a box with some tables -- is forgettable, and the menu a seemingly simple board of Southeast Asian classics. But what sets Pho Saigon apart is the cosmopolitan sense of otherness that comes from cramming in a mixed-demographic crowd and feeding them, in rapid-fire succession, foods that twenty years ago half the people eating here would have never heard of, and the other half would never have imagined eating in a little strip mall in Centennial. At Pho Saigon -- as in Saigon itself -- it's food that brings people together, food that gives them reason to pause in the middle of the day and enjoy something extraordinary. Pho is the big seller here (seventeen kinds, from a simple meatball version to the rare shrimp pho), but the menu stretches well beyond that to cover all the comforts of Vietnamese street food.