IN THE ROM-COM hit “He’s Just Not That Into You,” Ben Affleck, Ginnifer Goodwin, Bradley Cooper and other Hollywood stars meet in cute cafes, slurp cocktails at charming waterfront bars and play computer games in loft apartments with dreamy skyline views.

Is it another flick filmed in New York or San Francisco? Nope. The backdrop for director Ken Kwapis‘ ensemble piece turns out to be Baltimore, including the parks of Fells Point and the streetscapes of 19th-century ‘hood Mount Vernon. Thanks to a weeklong shoot, signs of the town show up in many scenes, like when Goodwin’s lonely singleton meets a pal at Fells Point pub the Waterfront Hotel (1710 Thames St.) or a down-on-his-romantic-luck boat driver moans about women from the nearby Ann Street Pier.

Kwapis, who shot the Kevin Bacon-Elizabeth Perkins romance “He Said, She Said” here in 1991, knew what many other auteurs do: Charm City’s varied landscape, old architecture and modest size make it an ideal spot to film a flick. This combo appeals to both directors looking to capture Baltimore itself (native sons John Waters and Barry Levinson) and those seeking a place to fill in for other locales.

“Baltimore has nitty-gritty urban blocks, narrow older streets, modern urban districts and beautiful monuments,” says Jed Dietz, director of the Maryland Film Festival. “You hear from film crews that it’s rare to see a city with such a variety of looks. If you can shoot 10 setups in a 30-block area, that’s huge.”

Waters, who still lives here part time and most recently shot 2004’s “Dirty Shame” on Harford Road, thinks films benefit from the city’s “easy mix of old and new,” he says. “It’s a place of hipster hillbillies.”

In 2005’s (seemingly) globe-trotting thriller “Syriana,” Baltimore played Dallas, Virginia, D.C., St. Louis and Geneva. “The city can look very European or English,” says Debbie Dorsey, director of the Baltimore Film Office. “Mount Vernon even stood in for 19th-century Paris in ‘Washington Square.'”

In that 1997 film, unlucky-in-love Henry James heroine Catherine Sloper (Jennifer Jason Leigh) visits a music store in Paris, actually the George Peabody Library (17 E. Mt Vernon Place). For much of the rest of the movie, she is courted by Ben Chaplin at Union Square (Hollins and South Stricker streets), where 19th-century townhouses and a park substitute for New York’s Washington Square.

Still, it may be D.C. that filmmakers use Baltimore for most often. “It’s a little different here, because we don’t have the government buildings. That often makes getting the permits easier,” says production designer Vincent Peranio, who has worked on all of Waters’ Baltimore movies since 1970’s “Multiple Maniacs,” Levinson’s “Liberty Heights,” and the TV shows “Homicide: Life on the Streets” and “The Wire.”

Peranio often sends crews to tony, rowhouse-rich Bolton Hill, which masqueraded as Kennedy-era Georgetown in the just-released Gretchen Mol indie, “An American Affair.” Nicole Kidman also leapt from a Baltimore Light Rail meant to be a D.C. Metro train in 2007’s “Invasion.” Will Smith fought Washington power brokers in “Enemy of the State,” but it was shot mostly in Baltimore.

Still, to really see the city on film — or trace the steps of actors from Divine to Adrien Brody — rent a few Waters or Levinson flicks, which showcase Baltimore in its own right. Both directors were born and bred here, so their movies capture the city’s personality in ways outsiders never could.

“John writes for places,” says Peranio of Waters. “Each film is an homage to a Baltimore neighborhood. He’ll pick his area, then drive around looking for where his characters would live. He casts houses like he casts actors.”

All of Waters’ movies use the city’s urban blocks and retail thoroughfares, but Waters himself thinks “Pecker,” his 2000 farce about a Hampden kid turned art world photographer, perhaps best catches its surroundings. “‘Pecker’ probably made Hampden look better than it did in real life,” he laughs. “I had a guy in the neighborhood ask me to sign his house after it came out. You won’t see that happen if you have a fake house somewhere else.”

Today, the Sub Shop (1101 W. 36th St.) where Pecker served roach-infested french fries still operates, but its Indian owners are dishing up sandwiches and a pretty good chicken tikka masala. Pecker’s mother ran a secondhand clothing boutique where coats went for as little as a quarter; it was actually David’s Thrift Store (914 W. 36th St.; 410-467-8159), where the 20th-century stock seems just as sartorially interesting, even if the prices aren’t quite that cheap.

“I shoot in places that inspire me, even if they’re down on their luck,” Waters says. That means he’s used spots such as the Holiday House (6427 Harford Road), a biker bar where, in “A Dirty Shame,” Ursula Udders (Selma Blair) works as a topless dancer, and the neon-decked, 70-year-old Art Deco Senator movie theater (5904 York Road).

The latter (which also figures prominently in Terry Gilliam‘s Philly- and Baltimore-filmed sci-fi masterwork “12 Monkeys“) recently shuttered due to financial problems, but cineastes in town think it’ll reopen soon. In Waters’ “Cecile B. DeMented” (2000), it served as a war zone of sorts, as guerrilla filmmakers took aging actress Honey Whitlock (Melanie Griffith) hostage in the name of “underground cinema.” The sidewalk outside bears concrete tiles painted in honor of premieres that’ve screened here from “Sleepless in Seattle” (filmed mainly in Fells Point) to “Diner.”

It is Levinson who views the city in perhaps the most flattering (and decidedly retro) light. “His vision is gentle, nostalgic and draws so much on his childhood,” says Dorsey. His four Baltimore films — “Diner” (1982), “Tin Men” (1987), “Avalon” (1990) and “Liberty Heights” (1999) — capture a place more wistful and elegiac than Waters’ somewhat rough landscape.

“Diner” depicts 20-something male friends (played by then up-and-comers including Kevin Bacon and Mickey Rourke) as they gab about girls, their futures and Frank Sinatra at the Hollywood Diner, at the time in Fells Point but now relocated to a corner downtown (Saratoga and Gay streets).

The 1954 chrome gem isn’t slinging malts these days, but nearby, circa-1950 Werner’s (231 E. Redwood St.; 410-752-3335), which served as a set in “Liberty Heights” and “Tin Men,” still doles out club sandwiches and meatloaf in a zone of butterscotch wood-paneled walls and Formica booths. “I do love a good time warp,” says Peranio.

Like many moviemakers seduced by Charm City, Levinson focuses on Mount Vernon, too, sending “Liberty Heights” law student Van Kurtzman (Adrien Brody) to study in the George Peabody Library and, in “Diner,” having Boogie Sheftell (Mickey Rourke) get beat up by a loan shark on Charles Street.

But it is in the opening of “Avalon,” Levinson’s tribute to the immigrant experience, that Mount Vernon becomes the ultimate soundstage. The scene depicts a young man in the early 20th century, just off the boat from Russia, as he strolls through Mount Vernon. It is the Fourth of July, and revelers in boater hats and Gibson girl dresses pass him as fireworks erupt above Baltimore’s gleaming Washington Monument. He is transfixed, and, in a voice-over says, “When I came to Baltimore, it was the most beautiful place I ever saw.” Taking in Levinson’s idealized cinematic vision, most movie fans would agree.

» Give it a whirl: See more of the ‘reel Baltimore’ in our photo gallery.

Photos by Marge Ely/Express, Frazer Harrison/Getty Images