With 18 seasons of "The Simpsons" complete and the long-anticipated big-screen adventure based on the classic in the can, you would think that Matt Groening -- the acclaimed creator of the Emmy-winning animated television series -- could be allowed some time to rest.

But for the lack of a better word, the answer awaiting Groening is a resounding, "D'oh!"

"I'm about to begin my international Springfield apology tour, from Springfield, Minn., to Springfield, New Zealand," Groening deadpanned in an @ The Movies online exclusive this week. "I warned Fox that when this contest was first proposed, that there were going to be a lot of upset Springfields who came in second. But I believe there are some consolation prizes."

Groening was joking, of course, in reference to the nationwide Springfield contest for "The Simpsons Movie," where 14 Springfields from Colorado, New Jersey and Florida, to Illinois, Massachusetts and Michigan vied for the dubious distinction of becoming the official hometown of the animated family (the Minnesota Springfield, afraid of its reputation being sullied, dropped out of the competition).

In the end, the honor went to Springfield, Vt., where a yellow carpet was rolled out over the weekend to host Groening and a couple thousand others, including the town's residents.

It's one of many ingenious ways (Kwik-E-Marts also springed up) that Fox, Groening and company have drummed up interest in the movie, which opens in theaters Friday.

It's only appropriate that the marketing approach for the film be irreverent, because, after all, that's what "The Simpsons" are all about. Not surprisingly, the film's PG-13 rating is for "irreverent humor throughout."

Still, Groening advised, the PG-13 rating isn't something that should frighten sensitive fans or young viewers away. Besides, some observers already liken the material in the television show to PG-13 content already.

"The movie is still very much family entertainment, but we push the boundaries gently with a little bit of language -- but nothing anybody hasn't heard on the grade-school playground," Groening said with a laugh.

Then there were other pains in the butt to deal with, like the response by some to, as Groening coined it, "the pseudo-notorious Bart skateboarding naked scene."

"We got some weird fan letters about that," Groening recalled. "They were worried we were going into a vulgar direction with it. But I wrote to all of them and said, 'When you see the way we do this, you will laugh. I guarantee it.' It's one of the best scenes we've ever done. It's very funny and there's nothing unsuitable for kids about it."

And as for unwritten PG-13 rule that allows one or two F-bombs, Groening assured that there's instead a three-letter word (with the help of an apostrophe and exclamation mark) in the script that reoccurs which packs much more wallop.

"When Homer (voiced by Dan Castellaneta) hits his thumb with a hammer, he still says, 'D'oh!' That's our expletive of choice and has been for a long time, which I think is very, very funny," Groening said with a chuckle.

Back To The Drawing Board

While the idea of a "Simpsons" movie actually dates back to the show's early years, Groening and the film's core group of writer/producers -- James L. Brooks, Mike Scully and Al Jean -- didn't embark on their trip to the big-screen version of Springfield until 2003, when the "Simpsons All-Stars" writing team began fleshing out the script.

"We wrote the script for two years and kept tearing it apart -- I can't imagine how many pages we must have gone through," Groening said. "Very little stayed in from the beginning to the end we changed so much. One writer quipped yesterday that we have two bad movies in the can to make up the good one."

Directed by longtime show collaborator David Silverman, "The Simpsons Movie" finds Homer with a new pet pig -- and in a crap-load of trouble when leaky silo full of droppings sets off a monumental disaster in Springfield. Thanks to Homer's biggest blunder yet, an angry mob storms the Simpsons household as a result, which forces Homer, Marge (Julie Kavner), Lisa (Yeardley Smith), Maggie and Bart (Nancy Cartwright) to flee the town a divided family.

In addition to President Arnold Schwarzenegger (Harry Shearer) and his EPA head Russ Cargill (Albert Brooks), the entire cast of Simpsons favorites also appear in the film, including Moe, Apu and Chief Wiggum (all voiced by Hank Azaria).

Without question, the biggest obstacle in creating "The Simpsons Movie" was coming up with a different spin, creatively, for the characters while maintaining the spirit of who the characters are. The last thing the creative team wanted was to create three episodes back-to-back-to-back (sans the commercials) and slap a "feature film" label on it.

As far as the characters were concerned, Groening said, it didn't come down to re-inventing the wheel -- just shining the hubcaps up a bit.

"For a while, we just tossed around what the expectations of the fans were and how we would honor the history of the show -- but then we just shoved all of that aside and decided to honor the people who worked on the show instead," Groening explained. "The movie is a showcase for all the great actors that we had from the very beginning, including Hank Azaria -- who came on in the middle of Season 1 and we still refer to as 'the new guy.' Plus, we gave the crew much more ambitious animation to tackle than they are able to do on the show."

Perhaps the biggest difference between the show and the film is the scope of it, Groening said.

"We knew that the story itself had to be bigger than a regular episode, and that it couldn't be a high-velocity, 'Simpsons'-style TV episode," Groening explained. "It had to be a real story that people got caught up in. That's a tall order for a cartoon that's been on the air as long as we have. We've done more than 400 episodes and that's a lot of different stories."

"But I think we came up with a really big, summer blockbuster-type movie with an eco-catastrophe caused by Homer as well as the oddball sorts of things that you would never see anywhere else other than a 'Simpsons' movie, including Homer's relationship with his pet pig and an encounter with a wise medicine woman in the Alaskan wild," Groening added, laughing.

Doing "The Simpsons Movie" created a weird parallel universe of sorts for Groening and company in that it was often times being produced at the same time the show was. There was a plan to treat the productions as separate entities, he said -- and for the most part, it worked.

"We kept the movie a secret from the TV show writers, but every so often, they would stray into territory that we were covering in the movie, like certain action sequences and jokes. They were instructed, 'Don't go there -- and we can't tell you why,'" Groening said, laughing. "They pretty much figured it out, and eventually, we included all the writers, and everybody who worked on the show threw in their two cents."

Bringing Back Brooks

Crucial to the production of "The Simpsons Movie" was the return of Oscar-winning filmmaker James L. Brooks, the creative force behind such film hits as "Terms of Endearment," "As Good As It Gets" and television's "Mary Tyler Moore Show." While he's been on board as an executive producer since the beginning, he was a show-runner in the series' crucial early years.

"At the very beginning of the series, when we first talked about turning the idea from little, 15-second cartoons on the 'Tracey Ullman Show' into a full-fledged animated series, Jim said, 'We have to go for real emotion and the goal, at certain points, would be to make people forget that they're watching a cartoon,'" Groening said. "On the TV show, we rarely do that anymore. We're more involved in the exuberance of the comedy style that we love so much."

But with Brooks' direct participation again, Groening said fans will notice a change back in the other direction.

"With the movie, we're trying to go back to the roots of the show," Groening said. "We're trying to choke people up at certain points. There's a core scene at the center of the movie with Marge where we recorded more than 100 takes of Julie Kavner trying different variations of this speech to make sure she got it exactly right. As it turns out, it's one of the times where the audience is very, very quiet in the theater. We're very pleased with the way it turned out."

One of the biggest questions surrounding "The Simpsons Movie" isn't about the movie itself, but whether the release of it is a bellwether for the end of the show. But with the announcement of the voice guest roster for the 19th season earlier this week, and the track record of another animated series after its run on the big screen, fans can take comfort: Groening, who is also heavily involved in the revival his other animated gem, "Futurama," said "The Simpsons" isn't going away anytime soon.

What he does hope goes away is a how people describe him as a certain Simpsons character: the Comic Book Guy.

"People pick the worst character on 'The Simpsons' to describe me," Groening goofed. "Where are the redeeming features? Couldn't it have been Moe the Bartender?"

Given his druthers, Groening said his Simpsons identity is actually divided between two characters.

"I'm a combination of Homer and Ralph Wiggum," Groening laughed.