New York museums attract tourists from all over the world... including single men who wish to admire Ron Arad's exhibit at the Museum of Modern Art. Single females can gaze upon more than just the paintings. In such a place, striking up a conversation about the virtues of impressionism as an ice breaker with a cute guy is perfectly acceptable. Should the conversation shift from abstract art to appetizers, welcome the opportunity to enjoy the rest of the exhibits together before grabbing a bite to eat at one of the cafes.
College students looking to meet other academics in the New York area should scout bars sporting NYU's violet torch right outside Greenwich Village. If Wall Street execs are preferred, "New York Magazine" touts Fizz on E. 55th St. as the best place to spot a man in a three-piece suit.
For the gay traveler trying to find a single man, New York City has a gay bar in every neighborhood from the Financial District to East Harlem. Even raw vegans who refuse to date men with a penchant for pork have a destination in New York---Caravan of Dreams and Pure Food and Wine cater specifically to animal-free diets. By doing some research on bars and restaurants that tailor to specific interests, the single woman (or man) is likely to be rubbing elbows with a like-minded complement.
Technology connects people in ways unthinkable just a decade prior. Instead of waiting to be approached by single men, plan a series of dates beforehand using the Internet. The New York City section of Craigslist has hundreds of postings daily from single men. By posting an ad explaining the situation of looking for a tour guide, many men would be happy to respond. These men can provide a tour of the city from the perspective of a native, or might be a fellow single traveler who would be happy to have a travel companion.
The other option is researching speed dating/single events hosted in New York City at the time of travel. In a new city, inhibitions can be thrown to the wind... especially in a city as large as the Big Apple.