BUFFALO, N.Y. — Clouds of white, fruit-flavored smoke hang in the air of a cool spring night, further obscuring the faces of revelers sharing a hookah on John Crandall’s unlit porch. They are friends and strangers, these eclectic souls who have convened here on this Wednesday in May.

Crandall, 31, a flight attendant with a saucy demeanor and Santa Claus physique, is drinking homemade cherry liqueur. Jennifer Colvin, 29, a debt collector and casino dealer, has just sucked down a cigarette. Theresa Campagna, 25, a Chicagoan in town accompanying her dad on a business trip, has plopped down on a metal-frame couch.

All eyes are on Jen Whitmore, a red-head wrapping up a story about a nightmare house guest who presented her with a gift she had to refuse.

“He goes, ‘But the thing I have to give you is kind of weird,'” the 26-year-old Whitmore says. Her eyes are so animated they seem to shine in the dark: “It’s a dildo shaped like Obama.”

The circle of listeners erupts with laughter, and soon after Whitmore finishes her vignette, two more figures emerge from the shadows of Richmond Avenue to join the get-together: Natalie Zayas, 44, a college lecturer from Monterey, Calif. and Jeff, 36, a professor from Brownsville, Tex.

He arrives carrying a six-pack of Blue Moon beer and business cards that are blank but for his name, engraved in a serious, black font: “J. GAINES WILSON, PHD.”

For Crandall, the scene and setting are typical. A few years ago, however, this casual weekday fête would not have been possible. With the exception of Wilson and Zayas, who met at a teaching workshop, the individuals who have assembled at Crandall’s house all know one another through CouchSurfing, an online network that matches travelers with hosts who offer a free place to stay.

The global community launched in 2004 claims more than 1.9 million members in 200-plus countries, according to statistics on its website.

Paris, London, Berlin, Montreal, Istanbul, Vienna, Melbourne, New York, Sydney and Buenos Aires are the most popular destinations. Buffalo, unsurprisingly, does not make the top-10 list. But its proximity to Niagara Falls means it’s still an attractive location, and in summer, locals like Crandall become the city’s informal ambassadors, entertaining visitors almost daily.

The friendships that form tonight over conversations about shisha in Jordan and toilets in Krakow might be fleeting.

But no matter. Within an hour, Zayas and Wilson are considering crashing at Crandall’s place instead of returning to the University at Buffalo in Amherst, where they are attending their workshop and living in a dormitory they describe as “soulless.” Campagna, a student and radio journalist, is arranging to sleep over at Colvin’s South Buffalo flat.

And that is the magic of CouchSurfing: Life becomes less predictable.

CouchSurfing means letting go of routine: smoking hookah with strangers on a Wednesday night. It means coming home from work one evening to find that German tourists have cooked you dinner. It means waking up one morning to discover a message from the most unexpected of people: a young man from Kabul inquiring if he can stop by in June.

Ben Breault, a 27-year-old teacher who calls CouchSurfing the “closest thing to a religion I have,” estimates that he has welcomed more than 150 surfers to his Allentown residence in the past three years. He has met Canadians, Danes, Australians, Kiwis, Israelis and a Colombian. One memorable guest was a white South African who talked about witnessing the end apartheid in his teenage years. (A disclosure: I met Breault and Crandall while hiking at Letchworth State Park last fall with a mutual friend, and have since had drinks with them and other CouchSurfers, including Colvin.)

CouchSurfing’s structure is similar to that of Facebook, with users posting photographs and personal information on profiles and maintaining a list of friends. But at its heart, the traveler’s network is different. Devotees call CouchSurfing a lifestyle, a commitment to learning and connecting with a diversity of people.

Colvin puts it this way: “It’s like bringing the world to my house. I don’t have to leave. I’ll have a crazy sense of wanderlust, but I can’t afford to travel at this point in time. So I get to bring the world into my home.”

Horror stories exist, of course—like Whitmore’s encounter with the dildo-wielding boarder, or Crandall’s brush with a Japanese woman who demanded that he lend her pajamas and, without warning, peeled back her jet-black hair—a convincing wig—to reveal a fuzzy head underneath. A young man living with Colvin reportedly ate a pretzel that was part of an art installation at a local gallery.

But participants insist that such outrageous tales are rare. (Whitmore, for one, points out that a friend who later housed her oddball guest actually hit it off with him.)

Individuals seeking and providing lodging through CouchSurfing can vouch for and leave reviews on other members’ pages, an arrangement that deters poor behavior. Users can also pay a fee—$25 for U.S. residents—to undergo a background check to confirm their address; those who pass become “verified,” a status that increases their credibility within the community.

The safeguards do not eliminate risk—in a well-publicized case, a jury found a host in Leeds guilty of raping a CouchSurfer in 2009—but the measures provide a level of protection.

THE STORY of the road, of exploration, is one whose mythos is embedded deeply in American culture.

Jack Kerouac romanticized hitchhiking in his 1950s novel “On the Road,” a fictionalized, autobiographical account of a writer’s cross-country odyssey. In the 1960s and 70s, the so-called Hippie trail carved a route through Asia that passed through cities like Istanbul, Tehran, Kabul, Dehli, Kathmandu and Bangkok. To this day, many U.S. college graduates look forward to backpacking through Europe as a rite of passage. The beatnik, Bohemian and wanderer remain idols of counterculture, symbols of open-mindedness and freedom from material things.

It would be unfair to categorize all CouchSurfers as new-age Kerouacs. No single label could fit the network’s members, who represent every one of the planet’s seven continents and speak upwards of 300 languages.

Still, something of the drifter’s tradition endures in the philosophy of the organization. Trust in strangers is essential, and many participants say that surfing is not just about traveling cheap, but about seeing what life is like in different parts of the world.

The idea for CouchSurfing came from Casey Fenton, one of the site’s four co-founders. After snagging a bargain plane ticket to Iceland for a long weekend, Fenton e-mailed more than 1,500 college students in Reykjavík, asking if he could stay on their couches. Responses poured in.

Today, CouchSurfing is not the only option available to tourists looking for a free night’s stay. Other networks, including Hospitality Club, BeWelcome and Tripping offer similar services.

Some volunteers and members have complained that CouchSurfing is poorly run, with opaque operations and a leadership team unresponsive to outsiders’ suggestions. But such concerns have not stopped CouchSurfing from becoming the largest exchange of its kind on the web.

In an age when a few words with a waiter or taxi driver might constitute the extent of contact a tourist has with locals, CouchSurfers are looking for a different kind of experience—one that moves beyond landmarks and souvenirs to unveil the inner workings of a city.

Breault recounts how, during a stay in Syria, he bonded with a Syrian soldier—a high school buddy of his host—over dinner and a trip to a Turkish bath, a hamam. By the end of their conversation, Breault’s new friend, who had known little about the United States, was saying he would like to visit.

Here, in Western New York, Wilson and Zayas did not end up staying with Crandall on their recent trip, but they did get to meet a bunch of Buffalonians and try hookah for the first time.

THIS YEAR, Forbes Magazine placed Buffalo eighth on a list of America’s most miserable cities. Cleveland took the top spot, with Detroit and Flint, Mich. close behind at No. 4 and No. 5, respectively. The ranking considered unemployment, tax rates, commute times, violent crime, weather, Superfund pollution sites, corruption and the performance of professional sports teams.

The Rust Belt’s showing was no surprise. These days, talk of the industrial north conjures visions of deserted factories, decaying homes and, in winter, mountains of snow. The imagery is overwhelmingly depressing.

CouchSurfing gives locals an opportunity to present a more nuanced view of the region. That does not mean hiding the ugly side of life in the Rust Belt. Breault, for example, takes travelers to the Central Terminal, the grand but abandoned art deco train station in Broadway-Fillmore, a neighborhood where vacant, rotting buildings seem perpetually on the brink of collapse.

But he also recommends Amy’s Place in University Heights and Nietzsche’s on Allen Street. He brought a Slovenian guest to a Buffalo Bills game, and a German one to the Erie County Fair. Once, after hiking in Zoar Valley, Breault and Crandall took six surfers to Crandall’s parents’ house in Ellicottville for burgers and beer.

A similar mix of activities filled the schedule of the second annual Detroit Couch Crash, a Memorial Day weekend “invasion” that drew hundreds of CouchSurfers to what is arguably America’s most-disparaged big city.

Events included urban spelunking at the Packard plant, a 3.5 million square-foot former automobile factory that now stands in ruins, a labyrinth of falling brick and concrete; a tour of city and suburban thrift stores; and a stop at Eastern Market, an open-air bazaar with fruits, vegetables, homemade jams and fresh-cut flowers. Some travelers made burritos for the homeless.

Couch Crash participants get “a real sense of what it would be like to live here, and what it’s like to experience Detroit directly,” says Nathan Andren, an organizer who opened his century-old home—with its single bathroom—to 13 attendees.

Surfers like sightseeing in grittier neighborhoods, he says, because they “want to experience what’s going on at the street level, whether or not it’s pretty or manicured.” But he adds that many leave with a positive impression of Detroit. The conversations and evenings out with locals who love their city—these are the things that, years down the line, the travelers will remember.

Whitmore says sharing Western New York’s secrets—Niagara Falls lit up at night, for instance—rekindles her own excitement about the region. She also takes pride in helping guests avert mistakes: Tourists always want to go to the Anchor Bar, she says, but “everyone knows that Duff’s is better.”

COLVIN, a native of Niagara Falls, remembers how, as a child, she and her father would take road trips to Toronto, where they would walk down Yonge Street eating pastries from Maison du Croissant. Her next international experience was radically different. After losing her job as a baccarat dealer at the Seneca Niagara Casino and Hotel, she went to teach English in China in 2004.

Her first days abroad were terrifying. After her flight touched down in Beijing, she bought a phone card and rang the school that had hired her. The woman who answered said because of a scheduling mix-up, a representative assigned to meet Colvin at the airport would not arrive until the following morning.

Unsure of where to go, Colvin latched onto an English-speaking taxi driver, who brought her to a two-story rooming house with no hot water. The bed, with a thin pad for a mattress, felt like a rock. The accommodations did not include pillows. Colvin spoke no Chinese. She started to cry. She had a one-way ticket and no money to get home.

In the end, Colvin fell in love with China. She eventually made it to her school in Handan, a city in Hebei Province a few hours by train from Beijing. There, she held dinner parties for fellow instructors from all over the world: a Lebanese ballerina with a Swedish passport, a Spanish-American poet, a stunningly handsome Dutchman. She ate jian bing, a breakfast crêpe, learned conversational Chinese and climbed some 6,000 steps to reach the top of a mountain in Shandong Province.

Despite the good times, Colvin’s memories of her frightening introduction to China have stayed with her. Maybe that’s why, back in Buffalo, she is the consummate host, keeping a futon, extra daybed and three air mattresses on hand for CouchSurfers.

She feeds visitors and leaves her laptop in the living room so they can use the Internet. She put together a binder holding information including public transit schedules and lists of attractions. Her generosity extends far beyond what the average person would give. She even provides instructions on how to get into her apartment when she is out.

“We’re taught to be very—you don’t do certain things. You don’t hitchike, you don’t take rides from strangers. You change your underwear every day. These things are what you’re taught to do without hesitation, without questioning,” Colvin says.

That is not the life she wants to live. Friends and family sometimes worry that she is too open, that a stranger could harm her. But she has a faith in humanity that some people would consider naive and others, inspirational.

Colvin returned to the United States from China in 2006 only after becoming pregnant by a Briton who left her. Struggling to make a living, she placed her baby girl for adoption. Even now, she has little disposable income.

She is hoping to go this year to New Orleans and Sweden—where she plans to CouchSurf—but for the most part, she does not have the means to travel. She does not own a car. Her evening commute to South Buffalo from her debt collection firm in Cheektowaga can take two hours: a ride on two buses and the metro.

In the days and months when Colvin is anchored in Western New York, hosting is a way to continue the adventure she began in China.

Many of her guests are on cross-country or around-the-world journeys. They are people who have decided to relinquish convention, to take a year off to see the Americas and Africa, Europe, Asia and Oceania. They are on what Colvin calls their “forever trip,” and by inviting them into her home, she gets to be a part of their experience.

She has been to Niagara Falls more times than she can count. But she still loves to go. She sees her city through the eyes of her visitors, and to them, it is all new—the rainbows, the towers of rushing water, the feather-light clouds of mist.

A year ago, Colvin began collecting notes from travelers in a journal. Some are simple messages of gratitude. Others are more intimate, filled with inside jokes.

Stacey from England thanked Colvin for “the cupcakes” and left a drawing of a brown chicken and a brown cow with a pink nose and udder. Martin and Andreas scratched out a brief letter in German and taped samples of European currency—all the coins but the 50 cent piece—on another page. Lesley and Alpa, the “Road-Trippin’ Midwives,” penned a missive in blue ink.

David wrote, “Ha sido mi primera experiencia couchsurfing y ha sido genial!! Espero que alguna vez vengas a España a visitarnos.” (“This was my first CouchSurfing experience, and it was great!! I hope you will come to Spain sometime to visit us.”)

The world is out there, waiting.