The Farrelly Brothers have made a career of dishing out a no-holds-barred brand of comedy that readily targets sacred cows and taboos. Their new movie is no different in this respect. Shallow Hal gets many of its laughs by simply watching an overweight woman and the man who finds her attractive. As they paddle a canoe across a lake, her end of the canoe sinks so far down that it nearly takes on water, while Hal's end of the canoe juts three feet up in the air. Or when she jumps into a swimming pool, a huge splash throws a boy out of the water and into a tree!

Writers-directors Peter and Bobby Farrelly get away with such blatantly insensitive material because they rarely actually show the woman in her rotund form. Instead, we see what Hal sees, a beautiful woman who would be the envy of any man. The comedy then comes not from the spectacle of watching an overweight woman nearly capsize a canoe or catapult a little boy out of a pool. The humor comes from the bemused expression on Hal's face, who is so in love that he can't begin to comprehend why Rosemary's side of the canoe would sink so precipitously or why a cannonball dive by Rosemary creates a monumental explosion of water. His love for her has placed the biggest set of blinders in the history of human courtship over his eyes. And this makes the potentially callous jokes palatable (and at times, absolutely hilarious).

In spite of the potential for mean spiritedness, Shallow Hal becomes the closest thing to a "sweet" or "warm" movie that the Farrelly Brothers have ever created. Now, this is relatively speaking, mind you. Shallow Hal will no doubt shock some people, but this is probably the least crude movie they have ever made. Instead of going for gross out jokes (such as the "hair gel" joke from There's Something About Mary), the Farrelly Brothers seem satisfied with creating an atmosphere of bemused confusion. The movie continuously courts "bad taste" but instead of plunging headfirst into the muck, the Farrelly Brothers play a delicate balancing act--giving us "fat" jokes while simultaneously turning the jokes upside down.

In the movie's early scenes, Hal (Jack Black) is an insipid babe hound. He has a vague idea that women aren't attracted to him, but that proves no deterrent whatsoever. On a dance floor, he ruthlessly pursues all the women. He slithers across the floor, his arms jutting out spastically, and then as he closes in on a woman, he grins like a Cheshire cat while spewing a non-stop barrage of drivel. Women absolutely hate him.

One day, Hal becomes trapped in an elevator with self-help guru Tony Robbins. As the hours pass, Hal talks about himself and his failed relationships. Robbins says Hal's view of women is shallow and recommends he undergo an attitude adjustment. Hal agrees and presto-change-o: Hal now sees the "inner beauty" of everyone he meets. Thereafter, Hal sees beautiful women everywhere. Not all women become beautiful. Not everyone has inner beauty. But the local dance bar is now chock full of gorgeous women who eagerly take to the dance floor with Hal.

Meanwhile, Hal's friend Mauricio (Jason Alexander) can't believe what he's seeing. He and Hal had shared absurdly high standards for feminine beauty. But now Mauricio sees Hal dancing with "a hyena, a hippo, and a stork." While Hal is in heaven, Mauricio begins to wonder about his friend's sanity.

The following day Hal sees a beautiful woman walking down the street. He parks his car and runs to meet her. However, the praise he lavishes on her meets a suspicious response. Rosemary (Gwyneth Paltrow) thinks Hal is treating her cruelly. She can't believe he really thinks she's beautiful. She's painfully aware that the rest of the world considers her horribly obese. But Hal is persistent and gradually she warms to him--and thus romance (of a highly unusual variety) is born.

This story could very quickly have degenerated into a one-joke affair (repeated ad infinitum) that endlessly emphasized what we already know--that Rosemary is seriously obese. (And yes, the movie does try to get too much mileage out of the joke where Rosemary's chair collapses at a restaurant.) But the Farrelly Brothers make this rather limited scenario work by making a convincing case that Hal's life is now much better. He's much happier. He's loving life. When he's with Rosemary, the "shallow Hal" of the movie's opening scenes begins to disappear. And Rosemary loves the attention and the opportunity to get close to another human being.

At the same time, however, we know this situation can't last--that Hal will eventually see Rosemary as she really is. Everything depends upon how the movie negotiates this inevitable (some might say predictable) turn of events, and thankfully the Farrelly Brothers keep the emphasis on the positive. I'm not going to reveal what happens, but suffice it to say Hal learns that he became a much better person when he was with Rosemary and loving her. And that's what makes this movie work, in spite of the potentially insensitive subject matter.

Much of the credit for Shallow Hal's success rests on the shoulders of its two stars. Gwyneth Paltrow gets buried underneath a fat suit for several scenes, but her best work comes in those scenes (sans the fat suit) where she has to convey Rosemary's doubts about Jack's sincerity. Paltrow uses a variety of subtle mannerisms to show us the barriers that Rosemary erects as Hal's praise turns into delusional palaver.

The movie's greatest miracle, however, is the casting of Jack Black as Hal. We've certainly seen him in an obnoxious mode before, as in High Fidelity, where he played a snobbish record store clerk who insults every customer that enters the store. But who would've thought Black could be so charming and optimistic? He makes this movie work with a performance that moves from manic intensity to gentle confidence.

Shallow Hal is evidence of the Farrelly Brothers' growing maturity as filmmakers. They've pulled back the gross jokes a notch and given us characters we can really care about. In the process, they've delivered one of the funniest and most imaginative comedies in years.

[rating: 3½ of 4 stars]