The best woman for the job might be a man. No, wait.. The best man for the job might be a woman. No, wait...

Boy oh Girl, things can really get confusing when Hollywood starts pushing the gender envelope, especially when actors insist on playing the opposite sex with verisimilitude.

The Inside Scoop The hottest celebrity swirl from the true Hollywood insiders: Marilyn and Stacy.   Hollywood Exclusive • Perils of Step-Parent Familiar to Terry Crews   Celebrity Gossip • CELEB INSIDER: The Fonz Meets The Boss     Ask BeckSmith • Paris Hilton made an album, but can she really sing?

But John Travolta, who plays Edna Turnblad in the July-opening big-screen adaptation of "Hairspray: the Musical," says he wasn't satisfied in just walking a mile in his character's quite ample girdle.

"I tried to make it so you never really knew it was me, that you thought it was some sort of eccentric overweight woman," Travolta told the Associated Press, speaking of the vision of perpetual voluptuousness he is wearing a fat suit and prosthetic jowls for his first musical role since "Grease" in the late 70s.

In advance screenings, audiences reportedly have not immediately recognized Travolta as the sweet, feminine apparition of Edna that took five hours of makeup a day -- and that's just what he wanted.

He reprises the role originated by renowned transvestite Divine in the original 1988 John Waters' film, "Hairspray," about Edna's daughter, Tracy Turnblad (played by newcomer Nikki Blonsky in the big-screen musical), a sweet, chubby girl from Baltimore who leads the charge to integrate a teen dance show on TV in the 60s. The stage version of Edna won Harvey Fierstein a Tony for Best Leading Actor in a Musical, and gave performers including Bruce Vilanch and Michael McKean an excuse to get done up in drag.

"It made me realize how much power women have over men," Travolta claimed. "You just need breasts and a bum and suddenly you have power! Guys would flirt with me on set. Everyone was feeling me. It was fake, of course, but I thought 'This is weird.'"

Travolta is just the latest in a line of actors who've taken on roles of the opposite sex in recent years - and not for laughs.

J.D. Pardo says it was the opportunity to explore the trans-gender world that drew him to play the title character in last year's Lifetime movie, "A Girl Like Me: The Gwen Araujo Story," the tragic true story of a teen beaten to death for living his life as a female.

"My personal journey on it was so intense and so meaningful - yeah, I learned a lot about acting, but it had nothing to do with that," says the actor, who's been seen such fare as "CSI: Miami" and the big-screen "Supercross." By the time he finished the picture, "I had come to realize how connected we are, male and female. I felt that I'd taken being a guy for granted, and it took me trying to become a girl to truly respect what it is to be a guy."

He recalls, "I knew going in, had to play this character as a human being and show this story to people. I knew the only way to do it right was to jump off that cliff and do it completely. This wasn't a drag show. In order to make it believable I had to become a girl, to find the girl inside me." To play her, Pardo went so far as to disappear from his normal life, telling his friends and his girlfriend he'd be "gone" for the duration of the production. He lost 18 pounds to fit into a dress, took voice training, waxed his eyebrows, put on a wig and makeup and went out dressed as a woman.

Even harder, says Pardo, was staying in character daily, "But I'd have to say the hardest were scenes where I had to wear a corset. I don't know how women breathe in those things!"

Of course, both Felicity Huffman and Hilary Swank can now say they don't know how men walk with those other things, er, family jewels if you will.

For her Golden Globe-winning, Oscar-nominated role as Bree, the man waiting for a sex change operation in "Transamerica," Huffman wore prosthetic genitalia beneath a girdle to identify with the character.

"When I started wearing Andy" - the cast and crew's nickname for her prosthetic - "which was about the second day of shooting in New York, it was different, I must say," Huffman told a reporter. "I know this sounds trite, but I understand why it's all guys think about because I put it in my girdle and it was all I thought about."

Hilary Swank, who took home her first Academy Award for playing Brandon Teena, the girl murdered for trying to pass as a boy in "Boys Don't Cry," said after she was offered the film, "I lived my life for four weeks strapping and packing which meant strapping down my breasts and packing a sock in my pants.

"There was a total physical transformation, which entailed cutting my hair off -- it was originally down past my shoulders. Then I did voice work deepening my voice and working on the accent I'd use. Then I looked in the mirror and wondered what on my face was most masculine, which was my bone structure, so I made that protrude by losing body fat," says Swank, who reportedly played loose with her health by dropping her body fat down to seven percent for the role. "When I walked around passing as a boy, I wanted to know what people believed and what people didn't believe."

"Almost Famous" hottie Billy Crudup also put himself through a physical transformation when he played 17th Century cross-dressing actor Edward 'Ned' Kynaston in the 2004 feature film, "Stage Beauty." At a time when women were forbidden to take the stage, Crudup's character became a star in women's roles renowned as much for his beauty as his talent.

To prepare for the role, Crudup said he "lost some weight, because it was more useful to fit into the corsets. I felt that that would exaggerate the sort of delicate quality that Ned supposedly wields so well. It helped with the androgyny."

Still, Crudup didn't find getting in touch with his inner woman as easily as Travolta did.

"I was not attracted to myself as a woman at all, quite frankly, and that was fairly disappointing," Crudup confessed to reporter Pam Grady, adding that playing a man who's playing a woman posed its own unique challenges.

"It wasn't just because I was being asked to play a woman, it was because Ned was meant to be so good at it, so convincing. I had never explored that part of myself and didn't really know how to go about constructing that artifice. It was important for the audience to believe the supposition of the audience of the time, which was that I was very convincing as a woman. That was a little bit scary, frankly."

Whatever they initially believed, it sounds like each actor who's walked a mile in the opposite sex's shoes was able to experience some profound insight.

Oscar-winner Dustin Hoffman has always maintained that his now classic gender-bending role as a male actor playing a female soap star in the 1982 "Tootsie" made him more sensitive to women and forever changed his life.

"I'm more emotionally connected with that movie probably than any part I've ever done," said Hoffman, who earned one of his six Oscar nominations for the role.

Perhaps Michael Dorsey, his male character in "Tootsie," sums it up best after Julie (Jessica Lange), the woman he's fallen in love with, finds out he was masquerading as Tootsie all along.

"I was a better man with you, as a woman... than I ever was with a woman, as a man. You know what I mean? I just gotta learn to do it without the dress. At this point, there might be an advantage to my wearing pants."

Pants schmants! Dress schmess! In the long run, it probably doesn't matter what we show on the outside as much as what we reveal from the inside. As Billy Crudup said, "There are so many places on the continuum between male and female and beyond...