NYC Discovery Walking Tours (465-3331): NYC Discovery Walking Tours offers 47 excursions divided into three categories: neighborhood, theme, and biography. "For the neighborhood tours," says Richard Anthony, firm historian, "we try and stay away from the cookie-cutter approach." Instead of showcasing the major attractions known to everyone, the neighborhood tours, called "The New York You Never Knew," highlight the more obscure but equally significant sites -- the house where Franklin and Eleanor Roosevelt were married, for example. For those who find that kind of historical arcana a bit dry, Discovery tours try to stay on top of pop culture as well: Among the current offerings are "Ragtime Era New York," "Titanic History Tours," and "Princess Diana's New York."
A Walk of the Town (222-5343): Marvin Gelfand uses the word mishmash a lot when describing his walking tours, and also when discussing the city itself. That seems only appropriate for someone with his hodgepodge of a background: Gelfand has held teaching positions in economics and history at Bard and the University of Massachusetts, was a literary editor at the Washington Post, and founded the West Side Literary Review. A born-and-bred New Yorker, Gelfand considers his personal experience one of his greatest assets: "I saw Frank Costello and Walter Winchell . . . I knew the Westies," he says. In September, he will be celebrating the Gershwin centennial with a tour of the theater district, including the site of the Liberty, where Lady, Be Good! played, and the Neil Simon, formerly the Alvin Theater, where Porgy and Bess opened.
Big Onion Walking Tours (439-1090): Big Onion was started in 1991 with a grand total of three tours. The outfit now offers more than 30 "multiethnic" outings, focusing on what founder Seth Kamil calls the "architectural and social history" of New York's neighborhoods. Big Onion, says Kamil (in a weary tone that suggests he's delivered this shtick before), is a metaphor for New York's "layers and layers of history, sometimes covered in a layer of dirt." A summer specialty: the new Thursday twilight tours, covering picturesque promenades like the Brooklyn Bridge, Central Park, and the Financial District.
92nd Street Y (996-1100): "History in the making" might best describe some of the unusual tours dreamed up by Batia Plotch, the Y's director of tours and travel. Instead of visiting the spots where great things once happened, tours like "Secrets of the Chelsea Hotel" and "Williamsburg's Burgeoning Art Scene" focus on areas with current cultural and societal importance, bringing the public into the studios of working artists. Plotch has also arranged for tours to visit the Fulton Fish Market -- at 6 a.m., when it's really hopping -- led by architectural preservationist Stephen Gottlieb and professional fish buyer Bill Bowers.
Radical Walking Tours (718-492-0069): Leon Trotsky. Malcolm X. Abbie Hoffman. According to Radical tour guide Bruce Kayton, "Every great radical has passed through New York City at some point." On his tours, which cover Manhattan from Battery Park to Harlem, Kayton discusses "the people who sacrificed their lives for a better tomorrow." His tour of Harlem, for example, includes the house where Marcus Garvey lived in 1917, the second headquarters of the Black Panthers, and the Unity Funeral Home, where the body of Malcolm X was displayed before his burial. People with short attention spans may want to stay away -- Kayton's tours can last as long as three and a half hours -- but those interested in the history of radicalism in the city will be rewarded by the depth of Kayton's knowledge and the occasional screaming attack by a rabid right-winger.