JOINER.(The Talk of the Town)

In 1998, a local man, aged forty, requested a legal name change for reasons that he no longer cares to explain. Out with the old ("and you're not going to find out what it was," he said recently), and in with--say it slowly--Leftonred Atanycorner. The new name suits his politics (he goes by Lefty) and hints at his rebellious streak. Other names he considered include Fail2yield Atalltimes and X. Sesivspeed.

Lefty is a freelance computer consultant and a world-class networker and social joiner. He belongs to more than four hundred clubs, and has supervised or organized twenty-six of them, including one whose theme was administrating more clubs. "I was the organizer of the organizers' group," he says. For a while, he kept a blog, Where's Lefty, "a 'Where's Waldo' for the modern socialista," in which he chronicled his schmoozy travels. (Sample entry: "Eric was a great host and offered us free Jello Shots before the movie and pizza during the movie. Way to go Eric!") Then he concluded that he was too busy meeting and greeting to record his impressions in a timely fashion, and he gave up.

Most of Lefty's group activities are coordinated through the Web site Meetup.com, where, for instance, origami aficionados or "Twin Peaks" fans or atheists (Lefty is all three) can find like-minded souls and arrange to convene. There are about ten New Yorkers--the Meetup Mafia, they call themselves--whose convening enthusiasm transcends subject matter. They are "high-volume attendees," as Lefty says, and Lefty is their don.

The other day, during a coffee break at a graphic-design seminar on lower Broadway, Lefty, who was wearing a pin-striped suit and an orange shirt, half unbuttoned, reached into his right jacket pocket and produced a stack of cards. "That's my business card," he said, presenting one for inspection. It read, "Middle Earth Media: We'll bury your problems," and featured an image of a hobbit with a shovel. (Lefty, a Tolkien fanatic, is by no means tall.) "Here's a sake card." It promised "an exciting and unpretentious atmosphere" and listed the Web site for the New York Sake Meetup Group. "And this one's a personal card." It featured a head shot and cited his blog. His left jacket pocket contained fifteen more cards: bounty from the morning's ...