LOS ANGELES -- When Dooley Wilson sings the line "A kiss is just a kiss" in the 1942 classic Casablanca, it takes only a moment's thought to realize that this was not true, especially in Hollywood. After all, what if Wilson, who was black, had attempted to kiss Ingrid Bergman, even on the cheek?

That taboo is disappearing, but the last big one remains: men kissing men. Now an important new film and three recent independents all have scenes in which male actors lock lips. The most significant kiss comes from Dennis Quaid, who is discovered by his wife (Julianne Moore) shirtless in passionate embrace with Jonathan Walker in the recently opened Far from Heaven. It is set in the 1950s when homosexuality was a crime in most of the United States.

Their kiss could become a turning point for several reasons. One is the rapturous reception critics gave the film in reviews that mentioned it as a possible Oscar contender. The director, Todd Haynes, 41, is a respected independent moviemaker whose unusual films are festival favourites. His last feature was Velvet Goldmine,about glitter rock, with Ewan McGregor as a David Bowie-style singer. Quaid is also an admired actor for The Big Easy, Frequency and The Rookie. He is a manly man, straight, and unworried about any typecasting from the screen kiss.

Even so, the scene made him nervous. "It took eight times to get it right," he said recently. "After the third take, when I got over the razor burn, it was just another day at the office. . . . I don't think it will hurt my career at all. I'm an actor and that's what I do, I reflect human nature. . . . There are certainly a lot of gay actors playing straight guys, so why not straight actors playing gay guys?"

Not many Hollywood actors have demonstrated such insouciance. When Tom Hanks played a gay lawyer with AIDS in Philadelphia in 1993 and won an Oscar for his performance, he did not kiss his lover in the film, played by the macho Spanish actor Antonio Banderas. In a recent television interview, Banderas said he had been willing to kiss, but Hanks declined.

In 1982 Harry Hamlin, now 50, made a film for Fox called Making Love, about a closeted homosexual doctor (Michael Ontkean) who leaves his wife for an openly gay writer, played by Hamlin. Their passionate on-screen kiss is still talked about by gay movie lovers, but Hamlin claims he never again made another studio film because of it. In recent years he has worked mainly in television and appeared in L.A. Law from 1986-91. He said: "I talked to a lot of people who saw the title, saw the people in it, and went with their dates or wives. Then they got to the kiss and were pretty shocked."

Even films that rejoice in depicting gay manners and mores usually balk at kissing. Nothing like that took place between Robin Williams and Nathan Lane as the amusing gay couple in The Birdcage, Mike Nichols's popular 1996 adaptation of the French comedy La Cage aux Folles. Nor did Robert Downey Jr. as an openly gay editor kiss Tobey Maguire's sexually ambivalent college student in Wonder Boys in 2000. Their relationship is implied but nothing overt happens on screen.

One must return again to 1982 for real lip-smacking action between major stars. It has been largely forgotten, but no less than Michael Caine and Christopher Reeve kissed passionately as gay playwrights plotting against a wealthy wife in the whodunit directed by Sidney Lumet, Deathtrap. It did not harm their careers, although some observers believe they may have lost some parts for a short while afterward.

Another forgotten male-to-male kiss was planted by an unexpected big name, the late, great Peter Finch, on his co-star, the then up-and-coming young Britsh actor Murray Head in 1971 in Sunday, Bloody Sunday. It was directed by John Schlesinger with Glenda Jackson and Peggy Ashcroft, but despite this distinguished company, the film was not a box-office success.

Another film from the seventies that included male kissing was Alan Parker's dark but engrossing drama Midnight Express, which did garner critical praise and went on to win a pair of Oscars.

In a strange twist, a more recent all-male screen kiss derived from Hanks's speech when he received his best-actor Oscar for the performance in Philadelphia. He thanked a gay teacher who had helped him at school, thus unintentionally outing the unsuspecting pedagogue. Screenwriter Paul Rudnick used this as the basis for his plot in the 1997 film In & Out, in which Tom Selleck, playing a gay reporter, gives a long and comic roadside kiss to a protesting Kevin Kline as the teacher.

But why the fuss when female-to-female kissing goes largely unremarked, or even celebrated, as was the case in the recent Kissing Jessica Stein? Scott Seomin of the Gay and Lesbian Alliance Against Defamation in Los Angeles, tracks the cause to male power and authority. "Most movies are made by straight men with a lot of power, and if you see another male yielding his maleness through a male-to-male kiss, which is seen as a feminine act, then this disturbs, because it fractures the notion of male power and authority," he said.

This may change -- at least a bit -- with Far from Heaven, and the recent independents, the sex-triangle Rules of Attraction from the Bret Easton Ellis novel, with Ian Somerhalder and James Van Der Beek kissing; All the Queen's Men, a Second World War comedy with British cross-dresser and comedian Eddie Izzard; and Love in the Time of Money, an art-house production set in New York described as a thoughtful antidote to the revolving "relationships" in the television series Sex and the City. The last three films are not big box-office, but they make all-male kissing a more routine affair.

Repetition is perhaps what will eventually defuse the shock that such acts seem to create. After all, as Dooley Wilson also sang, there is a minimizing effect "As Time Goes By."