Last year, Korean flavors went viral, and brought the rest of San Francisco's food scene with them. Thank Los Angeles for the boost: In November 2008, three Angelenos started up a taco truck called Kogi BBQ. Kogi drove around to different sites, selling Korean-Mexican street food like kalbi tacos and kimchi quesadillas, tweeting its location as the night progressed. Within months, the truck attracted crowds — hourlong waits or more — and write-ups around the nation. In San Francisco as well as Los Angeles, a critical mass of diners, many of them active on Twitter and Facebook, fell hard for the romance of transience, igniting this city's street-cart and... More >>>