When David Frankel agreed to direct the movie adaptation of John Grogan's best seller

Marley & Me

, he expected to shoot in Philadelphia at The Inquirer, where Grogan had been a columnist.

Frankel said he wanted authenticity, and liked the vast look of the Broad Street newsroom, which had been converted from a pressroom. So yesterday he, star Owen Wilson, and 250 cast and crew took over the city's largest newsroom for filming.

These days, filmmakers are coming to Pennsylvania not only for authenticity. They're also coming to save a few bucks.

Since Harrisburg boosted state tax incentives last year, Pennsylvania has become a hot place to do movie business. More than $500 million in projects are underway or planned during the next three years, said Michael J. Barnes, business manager of IATSE Local 8, the union that represents crew and technical workers.

The projects include M. Night Shyamalan's The Last Airbender (a trilogy budgeted at more than $250 million) and the eight-figure action flick Transformers 2, as well as smaller-budgeted independent projects and episodic television.

In the last two months, the region has been one big backlot, generating not only film business but excitement among celebrity watchers.

The comedy The Dream of the Romans began filming in Center City and Old City on March 17, with Lauren Graham and Jeff Daniels. The comedy Tenure, with Luke Wilson (Owen's brother) and Gretchen Mol, started shooting April 7, mostly on the campuses of Bryn Mawr and Rosemont Colleges.

And the drama Happy Tears, with Demi Moore and Parker Posey, began rolling on April 24 in Prospect Park, Center City and Old City.

Next month, filming of Michael Bay's Transformers 2 with Shia LaBeouf and Teresa Palmer will begin, and two TV series - FX's It's Always Sunny in Philadelphia and CBS's Cold Case - will return for another season.

Two major studio films were shot here last year: Shyamalan's The Happening with Mark Wahlberg and Zooey Deschanel, in theaters next month, and Peter Jackson's adaptation of The Lovely Bones with Wahlberg and Rachel Weisz, due next year.

Producers are stepping up work, in anticipation of a possible Screen Actors Guild strike this summer. Talks continue on a new contract.

Locally, the business boom is "allowing people to step up," said Diane Heery, a Philadelphia casting director. "Someone who's been a [production assistant] can be a second assistant director. It's opened up the market."

While trying to lure filmmakers from such traditional locations as Canada and California, states seem to be tripping over themselves to pass tax incentives to offset film-production costs. Producers use incentives to leverage financing or sell them to brokers who resell them to residents or businesses, who use them to offset tax liabilities.

Tax incentives are "hugely important," Frankel said between takes yesterday. "You see instant results when states embrace an initiative."

Proponents say they drive local economies, filling hotel rooms and restaurants and keeping skilled workers employed.

Connecticut, New Mexico and Louisiana were among the first to offer film tax incentives, followed by Rhode Island, Alaska, Tennessee, Michigan and New York. This month, Mississippi and Georgia sweetened their offers.

Pennsylvania last year instituted a 25 percent tax credit for production expenses incurred in the state, up to $75 million a year. Legislators also are considering $10 million grants each to developers of movie studios planned for Delaware County and Montgomery County.

In the industry and government, much of the credit for the city's place on the cinematic map is pointed toward Sharon Pinkenson, executive director of the Greater Philadelphia Film Office, which lures filmmakers, maintains a database of hundreds of industry workers, and works with police and other agencies to accommodate crews.

This week, while crews set up all over town, Pinkenson is at the Cannes Film Festival, trying to drum up business.

In 1992, Pinkenson was a freelance commercial stylist who was looking for work for herself and her friends. After reading an article about a film boom in Pittsburgh, she asked mayor-elect Ed Rendell to revive Philadelphia's film commission, which had become moribund because of budget cuts.

She handed Rendell a proposal for what she called the Greater Philadelphia Film Office. "I planned out an idea that the film office had to be regional," she said. She insisted that she didn't want to run the office, but Rendell demanded a business plan.

Pinkenson said she wasn't happy with the applicants to run the office - "they think all it means is going out to lunch with Harrison Ford" - so she stepped forward, working at first for $1 a year.

Funding quickly followed, she went full-time, and the office grew. It now is a nonprofit, no longer a city agency, with a full-time staff of eight and a $1 million budget.

Pinkenson counts about 400 film-industry workers in her production guide, plus a contingent of about four times that many working part time.

About half of the Marley crew is from the Philadelphia area. During a break, makeup artist Diane Heller and hairstylist Diane Dixon, veterans whose credits include Shyamalan's films, said they thought the tax incentives were responsible for their new work. Heller also thought that the Philadelphia area - "rural, cosmopolitan, a little bit of everything" - made it desirable as a location.

Marley, whose production budget has not been disclosed, began shooting March 10 in Fort Lauderdale, Fla., where Grogan and his wife, Jenny, lived when they acquired Marley. About two dozen dogs are being used in the movie, said Frankel, who has five of his own.

The production will set up next at a farmhouse in Birmingham Township, Chester County. Then they're off to Ireland for vacation scenes with Wilson and his costar, Jennifer Aniston. The movie's scheduled release is Christmas Day.

During filming yesterday, reporters and editors viewed the goings-on - which more than doubled the newsroom population - mostly with amusement. Wilson, as Grogan, and an editor played by Clarke Peters (The Wire) walked through the newsroom and met in the editor's office, which is the real-life office of Inquirer editor Bill Marimow.

Business writer Jane M. Von Bergen went about her day's work with a union extra at her side. When the extra seemed bored, Von Bergen asked her to open some mail. The extra, Von Bergen said, managed to get through the mail that filled two large plastic tubs.

For video of Owen Wilson and the making of Marley & Me, go to www.philly.comEndText

Contact staff writer Michael Klein at 215-854-5514 or mklein@phillynews.com.