Subways and yellow taxis may be the icons of New York transportation, but it is the bicycle that has the longest claim to New York's streets: two hundred years and counting. Never has it taken to the streets without controversy: 1819 was the year of the city's first bicycle and also its first bicycle ban. Debates around the bicycle's place in city life have been so persistent not just because of its many uses--recreation, sport, transportation, business--but...