The star of Hot Fuzz and Shaun of the Dead talks about his upcoming roles in Run Fatboy Run and Star Trek.

After his satirical genre sends-ups Hot Fuzz and Shaun of the Dead with partners Nick Frost and Edgar Wright, British actor/writer Simon Pegg is an unqualified cult hero. So his fans might be a little surprised to discover him starring in Run Fatboy Run, a romantic comedy without a hint of tongue-in-cheek about it.

"I think what I liked about this film was the fact that it wasn't that. It is a romantic comedy and it fulfills a lot the criteria of a romantic comedy. It's not particularly innovative narratively; it follows those beats that you would hope to get from a romantic comedy, and that's why people go and see romantic comedies," explains Pegg. "But at the same time we hoped to give it enough of an edge to make people know that we are aware of that and they're aware that we have appropriated a very oft-tread path."

Pegg's Fatboy character is a lazy guy who leaves his pregnant fiancée (played by the stunning Thandie Newton) at the altar and tries to win her back by running a marathon -- for which he is very ill prepared. The characteristically trim Pegg seems an odd choice for an overweight slacker character -- especially since he shot the part fresh off his role as superstar police Sgt. Nicholas Angel in the cop/action movie send-up, Hot Fuzz. But his Friend (haha) and Fatboy director David Schwimmer saw past Pegg's fit physique.

"I'd known David since Band of Brothers, although we hadn't really spoken in those days because he was more famous than me," he jokes. "David contacted me a while ago, about four years ago maybe, when the script first came up. And I read it and liked it. And then it kind of went away, really, I didn't hear about it again."

But when Pegg and Schwimmer were playing opposite each other on 2006's Big Nothing, the topic came up again. "He said on set, 'This is still around if you're interested.' And I said I was," says Pegg. "And then it definitely became something that was going to be filmed in London and would need to be rewritten because the original script was set in New York. And I, being a writer as well, took on the duty of translating it to London and doing this second draft on the script."

One of the best parts about Run Fatboy Run for Pegg was working with co-star Thandie Newton, who turns out to be much more of a pistol in real life than the characters she usually plays. "She was all about practical jokes. She was a relentless joker," he recalls. "I always felt flattered that she was spending that much time thinking about me. She clearly devised these ridiculous jokes--she left things in my toilet, she sewed up my clothes. She was like a Batman villain, she was that sort of pre-conceived. She was a terror."

"My way of getting back at her was to not rise to it," Pegg continues. "I'd go into my trailer, something would fall on my head, I'd discover a pair of soiled underpants in my toilet that the facility guys had clearly seen -- because they'd just clean and thought, 'Wow, Pegg's horrible!' And I'd just come out of my trailer like nothing had happened."

But after Fatboy, what Pegg fans and sci-fi geeks alike are most excited about is his upcoming appearance in J.J. Abrams' Star Trek. In it, Pegg takes on the iconic role of Scotty. And although he finished shooting last week, he is staying strictly mum on the subject. "The minute I open my mouth a bullet will come through that window. A dart will hit me in the neck and I'll just go unconscious," he jokes.

But even if he won't give up any plot details, Pegg still has a little bit to say about Abrams' direction. "The thing that's great about him is that he's an enthusiast, he's a movie-lover, he's a geek like me, he's a fanboy," says Pegg. "I think if I wasn't involved with Star Trek and I knew they were making a new film, I would want someone who is a fan of the franchise to make the film. And that's what's happened."

As for playing Scotty, don't expect Pegg to just be doing an imitation of the role's originator, James Doohan. "I think that would have done him a disservice and could have been seen as me making fun, which is the last thing I wanted," he explains. "Those guys created some of the most significant characters in contemporary science fiction and this film is entirely in deference to that. I didn't want to go off and just pretend to be James Doohan. I wanted to be Scotty, and I wanted to do that in his honor."

Interestingly, like Doohan, Pegg isn't Scottish. But luckily he had a good accent coach. "My wife is Scottish and I spend a lot of time in Scotland every year, and I would hope that constant proximity to the Scots has enabled me to play the part," he says. "She was on set a lot of the time and I'd come off saying, 'Did that sound all right? Was that Scottish?' and she's go, 'Yup.' She was my yardstick for the whole thing. Also, she wanted me to play West Scotland rather than East because she's from Glasgow."

Run Fatboy Run hits theaters nationwide on Friday, March 28, 2008.