You can be the mayor - anywhere

As all the world knows, the Honorable Michael Nutter is the mayor of Philadelphia.

Not in the world of Foursquare, though. In that social-media world, the mayor of Philadelphia is some guy named "Frank S.," from New York.

In Foursquare, there's a mayor of the Ben Franklin Bridge, too - EricaLynn Gruenberg of Oaklyn.

The mayor of the Philadelphia Museum of Art is John Ingram of Lansdale. And the mayor of the NJ Transit train between Atlantic City and Philadelphia is Trisha Winter of Vincentown.

In Foursquare, people with smartphones register their whereabouts and share them with friends. You "check in" wherever you are - City Hall, Rittenhouse Square, the Liberty Bell, the Piazza at Schmidts. Almost any place that's a place, you can check in. And if you check in the most, you can become . . . the "mayor" of that place.

As in a video game, mayorship brings instant rewards. "Anyone else who checks in to that place," explains Mitch Rozetar, 21, an Art Institute of Philadelphia student from Sinking Spring, Pa., "is told you're the mayor."

Like Facebook, Twitter, and other social media, Foursquare helps friends stay in touch and groups come together based on shared interests. But it's also addictive, a mad game of points, badges, mayorships, and "specials" - discounts, free food and drink, free stuff - that encourage and reward the alert and curious. Says Rozetar: "Foursquare rewards you for going out of your comfort zone and trying new things."

The fame game

"There's a sense of fame to it," says Rozetar, mayor of Reading Terminal Market.

Brandon Thomas, 28, a restaurant manager for Jose Garces (and mayor of the Piazza), says, "I'll be walking through my restaurant, and a group will scream my name, 'Hey, Brandon!' . . . In shock, expecting the worst, I see Foursquare on their phones, and they say, 'It's great to meet the mayor.' "

"I use it pretty much daily," says Ingram, 26. Besides the Art Museum, he has the mayor's keys to 15 places including Steel City Coffeehouse in Phoenixville and the 40th Street beach in Ocean City, N.J. "I got my first mayorship and just took off."

Thomas' job naturally led him to the Piazza. "It took me two months to become the mayor," he says. "I've been living here for nine months, and it's a constant struggle to keep my mayorship. If I forget one day, I lose it."