A smokin' trend finally is catching fire in Pittsburgh:

We've got a hookah bar.

A who what?

Annie O'Neill, Post-Gazette Carnegie Mellon University senior Audley McBrian Oswin Wilson Jr., the principal owner of the South Side's new HKAN Hookah Bar & Lounge, releases a cloud of jasmine and rose hookah smoke. Click photo for larger image. HKAN is now open from 6 p.m. to 2 a.m. Thursdays through Sundays (an hour later Fridays and Saturdays). Soon it will open at 11 a.m. Tuesdays through Saturdays. The phone number is 412-381-1812; the Web site, not yet up, will be www.thehkan.com. Customers choose one or a combination of what is to be 50 flavors. One hookah, which serves up to six and lasts about an hour, costs $6 for regular tobacco, $8 for premium.

S o nightcrawlers have been wondering as they walk and drive past this unusual new establishment on Carson Street in the South Side.

A hookah bar is a place where you smoke hookahs, or Middle Eastern water pipes. They've got a shelf full at the HKAN (pronounced H-con) Hookah Bar & Lounge at 2210 E. Carson St.

Not quite completed, the place started opening earlier this month on weekend nights, advertising by having people puffing on these curvy glass contraptions out front.

Puffing what is the question.

The answer is shisha, traditional mixtures of tobacco and fruit pulp, molasses and honey.

"No hash?" asked one smart-aleck Friday night, when passers-by took pot shots at the pipes, notorious for being used for illicit drugs.

But this smoke is legal. It comes in a surprisingly G-rated range of flavors, from apple and mango to cola and cappuccino. Aficionados and first-timers alike say it's much milder and sweeter than cigarette, cigar and, uh, other kinds of smoke.

"I meet very few people who don't enjoy it," said Audley McBrian Oswin Wilson Jr., the 22-year-old principal owner and CEO. The Jamaican-born, New York City-raised Carnegie Mellon University business major created the hookah bar for an entrepreneurship class. Launching it during his final semester isn't easy, "But I don't have to worry about a job, I hope."

He got the idea the winter before last after visiting one of the estimated 200 to 300 hookah bars that have sprung up in New York and in cities all over the country since the late 1990s. They've smoked oxygen and cigar bars for popularity, especially among the college crowd.

One of the hookah Web sites -- www.southsmoke.com -- has a Top 12 list of bars, from simple Sinbad in Pacific Beach, Calif. (which the owners want to franchise), to trendy Tantra in Miami Beach, Fla., where dinner for two with wine can cost $180.

Wilson said he and his investors don't fear the fad fading, "because in the Middle East, these things have been around for thousands of years."

Actually, the pipes -- variously known as narghiles, shishas and hubble-bubbles -- have been around for hundreds of years. No one's sure where they originated, but the Web site www.sacrednarghile.com traces their "mysterious origins" to Africa before 1600. By then, the pipes had blazed a path from India to the Middle East and Turkey, where smoking flavored tobacco became infused with the culture.

The pipes reportedly have become hot again there and in Europe with the young and hip.

Don't confuse them with smaller "bongs" used to smoke marijuana and hashish that are outlawed in the United States. Wilson says that shadow made some Oakland landlords reluctant to rent to him, but he's happy where he wound up. "South Side is very open to new ideas."

Servers explain to the uninitiated how hookah works. Customers choose one or a combination of what is to be 50 flavors. One hookah, which serves up to six and lasts about an hour, costs $6 for regular tobacco, $8 for premium.

Annie O'Neill Raz Tirosh, left, and Dan Braido were among those smoking hookahs Friday night at the HKAN Hookah Bar & Lounge. It's not unusual for patrons to smoke more than one bowl of shisha tobacco in an evening. Click photo for larger image.

The moist tobacco mixes are packed into a bowl atop the pipes. HKAN's hookahs, from Jordan, are made of glass and stainless steel and can be taken apart for cleaning between uses.

The mix isn't directly lit. Foil is placed over it, and small pieces of lemonwood charcoal are placed atop that, to superheat the mix. Staffers start drawing the smoke, which passes through water as smokers suck it through the flexible hose. Smokers either share the same tip or insert disposable ones, which the bar provides.

Because the water cools the smoke, you don't know it's in your mouth until you exhale.

"It's really mellow," said Wilson, who hated cigarettes when he tried them. With a hookah, he fills his lungs completely -- the water goes bubble bubble -- then exhales a cloud of white smoke that smells of jasmine and rose petals. "Very relaxing."

Maybe not the first time.

"Are you supposed to smoke this like a pipe?" asked Justin Donaldson, 26, of Swissvale, who ordered a lemon flavor to share with a table of friends.

"I don't think you're supposed to inhale," said one, 38-year-old Eric Brunson of Columbia, Mo.

Pooja Aggarwal, 22, said she was familiar with hookahs from her native New Delhi, but she wasn't sure she wanted to try this one.

Donaldson did and was surprised. "That tastes really good."

Brunson agreed. "It's cool."

Others in the mostly 20-ish crowd (you have to be at least 18) said they wouldn't smoke cigarettes. But smokers said the hookah smoke contains so little nicotine that they'd smoke a cigarette before or after smoking a hookah. A group might smoke as many as four or five bowls in an evening.

Wilson claims shisha is only 30 percent tobacco and contains 0.5 percent nicotine and no tar. But he says servers -- and soon, signs -- will warn customers of the potential dangers.

The medical establishment takes a dim view of hookahs. In 2004, an American Cancer Society study, which showed that pipe smoking is as risky as cigar smoking, pointed out that hookahs are being marketed as "a trendy, fun and less hazardous alternative to cigarette smoking." However, warned epidemiologist Jane Henley, "The significant risks we found should leave no doubt that all tobacco products cause disease and death."

HKAN does not have a liquor license yet. In the meantime, it is allowing people to bring in their own beer and wine and charging a corkage fee. Patrons are asked to purchase at least one $1 to $1.50 soft drink -- soda, coffee or tea. In a few weeks, the kitchen will open and serve Mediterranean lunch and dinner.

Since it seats only 50 people, HKAN is not required to have a nonsmoking section.

On Friday night, the place wasn't mellow. It was packed and noisy as a band played. But the vibe was good, faintly exotic, and the diverse crowd seemed to be enjoying themselves in the cozy space, designed by and named for Wilson's friend and frat brother Hakan Bakkalbasi.

A few hookah fans sat at tables on the sidewalk outside, including Anwar Alshuail from Kuwait, puffing on his favorite: double apple. The 35-year-old petroleum engineer, in Pittsburgh while his father waits for a heart transplant, just happened to walk past as Wilson and his friends were working on the space and was thrilled, since back home he spends most afternoons smoking his own pipe with friends at a cafe.

That social aspect seems to be as big a draw as the hookahs. "You can hang out and talk here instead of sitting at home in front of the TV," said 24-year-old South Sider Tia Robinson, adding, without a trace of irony, "It's a lot better than sitting in a smoky, loud bar getting trashed."