Benjamin Sann was a 16-year-old sophomore at Horace Mann when he dreamed up the idea for a Website that compares parking rates in Manhattan. Inspired by the Seinfeld episode where George refuses to pay for a garage, Sann dedicated four months of his life to pedaling around Manhattan on his three-speed Dahon fold-up bicycle, then built his Website with a team of freelance coders. Since nycgarages.com launched last spring, the site has clocked almost 600,000 page views, opening the eyes of the world to the astonishing price irregularities of Manhattan parking. Enter where and when you want to park, and it spits out reams of figures. In the theater district, you’ll learn, six hours can be $11 or $50; a monthly spot in Tribeca runs from $326 all the way to $793. Soon, the service will work on mobile browsers, where it will be of greatest use, though not to Sann, who is now a college freshman but still doesn’t drive. “I’m going to be taking driver’s ed this summer,” he says.