Arabs! Jews! Lighten up!

At the end of their shows, the unlikely duo of Rabbi Robert Alper and Muslim comic Ahmed Ahmed let the laughter die down so they can get serious.

It doesn't matter if the gig is in a synagogue, yet backed by an alliance of Jews and Muslims, or in a community center, with a smattering of Christians in the crowd. The duo has even performed one show in a mosque.

"We know what people are thinking. They've been laughing together all night, but things are still a little tense," said Alper, who has been a professional comedian and part-time rabbi for 17 years. "So we talk to them in very serious tones for few minutes. We say that we know terrible, tragic issues divide our people. We say that we're not politicians or social psychologists. We don't have the answers.

"But there is hope. We have found one thing that can bring us together."

The room falls silent. Then the Celtic "Riverdance" music blasts out of the sound system. The gray-haired Reform rabbi from Vermont and the edgy Arab funnyman from Hollywood start dancing. The result is kind of Irish, kind of Arab, kind of Jewish and totally goofy.

"It works," said Alper. "I think people come out to see us because they expect some kind of healing experience, and that's what it is. It's a start."

They call the act "One Arab, One Jew, One Stage." But sometimes the post-Sept. 11 duo gets a more daring billing: "Arabs! Jews! Lighten Up!"

Easier said than done. At a recent South Florida show, people were more concerned about the local history with Mohammed Atta and his al-Qaeda cell than Jerry Seinfeld and company. The audience filed past three Boca Raton police cars and the concrete planters that block the synagogue driveway. It didn't help that this was a day when Al-Jazeera was airing forced interviews with American POWs and images of dead GIs.

One Orange County, Calif., show was sponsored by an alliance of Jews and Arabs. Bantering with Muslims in the audience, Ahmed noted that security guards frisked him beforehand and he assumed other Arabs got the same treatment. A Jewish man a few rows back called out: "Hey! They patted us down, too." Oh great, cracked Ahmed. Now they frisk the Jews as they enter the synagogue. That's progress.

Nervous laughter is a given, once the Egyptian-born comic starts sharing what life is like for a young, bearded, Muslim frequent flier. He goes to airports a month and a half early. His in-flight meals are pre-cut, since no one will give him a knife. When jittery travelers ask his destination, he says he has a "one-way ticket to paradise." He pauses and adds, "Hawaii."

Nevertheless, Ahmed says Jews and Muslims have a lot in common. They don't eat pork or celebrate Christmas. They use that throaty "CCCCHHHHH sound" a lot, as in l'chaim. "We're both hairy creatures of God," he added. "The major difference is that Jews don't like to spend any money and Muslims never have any money to spend. ... So let's all get along and share, people."

Actually, anyone who pays attention can find other common elements in the routines. The comics could swap scores of jokes about ethnic traditions and family life without missing a beat. It's clear that Muslim and Jewish mothers have much in common. Many urban and suburban Muslims feel more at home in modern America than their elders. When Ahmed announced that he wanted to be an actor, his father shouted, "But God does not live in Hollywood!"

Once upon a time, said Alper, Jewish immigrants faced this painful assimilation process and they struggle with it still. Yes, the two comics steer clear of politics and it's hard to joke about their faiths. But these are not the only taboo topics. Take the issue of intermarriage. Please.

"We can't make people too uncomfortable," said the rabbi. "You use a joke that takes them down low and their minds go off to some place that's really painful and you can't get them back. We can't do that, yet. It's too personal. We're just getting started talking about these kinds of issues and we have a long way to go."