When Brooks Mar, a 26-year-old associate at Lehman Brothers, took a year off, he did it to prove that his life was not run by money or the expectations of anyone other than the guy he met each morning in the mirror. Mar began by traveling the world. He learned to scuba dive in Southeast Asia and hiked through the Thai jungles near Chiang Mai. For fly-fishing and glacier-trekking, he headed to Argentina. But three months into his journey, while learning to surf in Florianópolis, Brazil, inspiration struck.

Florianópolis is a paradise, with beaches, amazing surfing, and thriving nightlife overflowing with beautiful women. As Mar looked at all the cheap space for rent near the beach, a longtime dream of opening a bar suddenly seemed within reach. He IM'd three buddies back home, convincing them that for $15,000 each they could own shares in his tropical fantasy. Nine months later, with his new Brazilian girlfriend at his side, Mar and 300 guests celebrated the opening of his hot new club, dubbed Molokai. He had transformed himself from an ordinary young banker into a minor celebrity – the enterprising young American in Florianópolis. His new full-time job was to be the life of the party, and he discovered he had a natural talent for that role.

"Taking that time off made my life infinitely better," says Mar, who is now back in the States working in finance while one of his partners takes his turn operating the club. "After you challenge yourself in that way, you have a different outlook on the problems you face and the people you deal with," he says. "You carry a confidence with you that you can apply to any career and any challenge in your future. You can't put a price on that sort of experience."

Men across the country have begun to embrace the notion that stepping out of their day-to-day routines for a year is not only a fantasy worth fulfilling, but an essential part of their professional and personal growth. There's even a growing industry of life coaches, adventure schools, and financial planners all catering to the trend. Major companies, which in boom years offered sabbaticals to retain sought-after employees, are using minimally subsidized break periods as both a kind of temporary layoff during lean years and a way to keep top people during boom times. According to one survey, 18 percent of Gen X employees have either taken an extended break or have one planned in the future.

Although it's becoming more common, a year off is still definitely not for the timid. Men who have had the courage to take an extended break advise that it isn't an introspective retreat from the world. It's a complicated endeavor that, handled badly, can jeopardize your job and your relationships back home.

Given the risks, the payoff should be equally high: Don't make a list of what would be "fun"; make a list of the toughest challenges you'd dare to take on. Don't think "trip"; think "quest." No one else gives you permission to take a year off – and no one else signs off on your plans or goals. A year off proves that a man is in control of his own destiny.

We talked to dozens of men who were up to the challenge. Their stories serve less as specific roadmaps than as profiles in "going for it." Taking a year off can mean sailing the world or starting a nonprofit. One man ended up on a remote island building a house with his buddies, while another decided to travel the world and hook up with as many beautiful women as possible. For Al Hamlin the perfect year meant becoming the ultimate sports fan. Robert Tassi's year took him from a six-figure music-industry job in Nashville to becoming the lowliest deckhand on a Maine coast schooner. No one's year off is the same, and no year off ever goes exactly as planned. Some men emerge re-energized and recommitted to the world they left; others use it as a launching pad and never return to their previously scheduled lives. But all the men we spoke to had one thing in common: Not one regretted his decision.

A year off is not a vacation. At age 35, Dana Magenau learned this lesson the hard way. His original goal was just to take a few weeks off to climb Aconcagua, the highest peak in South America. But he wasn't a climber – he was an international vice president of the sports marketing firm IMG. So he decided to take night classes to learn techniques for climbing in ice and snow at high altitude. He trained hard at the gym and read every book on mountaineering he could find. At his desk, he visualized the challenge. He figured the whole thing would take less than a month.

In reality, the 22,834-foot-high mountain kicked his ass. Twelve days into the trip, unaccustomed to Aconcagua's altitudes, Magenau was concerned that his massive headache was a sign of acute mountain sickness. He tried one more summit push in the middle of the night, and then retreated downhill. "Turns out I was fine," Magenau says. "I went back to work thinking, Well, that was just miserable. I'll never try that again."

Back home, he remembered the mountaineer's maxim: "Attitude gets you altitude." You can be in great shape, but if you don't have the mental fortitude to ignore the pain that comes with climbing and take the next step uphill, you're cooked. So Magenau made a plan for an epic year off built around becoming a real climber, a year that would take him across four continents, then back to an emboldened life and more successful career in America.

First he climbed Island Peak in the Himalayas, where he got some generous counsel from famed Everest climber Wally Berg. He traveled to Africa and climbed a difficult route on Kilimanjaro. And a little more than a year after his failed attempt, he found himself back at the foot of Aconcagua. This time, Magenau kicked the mountain's ass.

"You can accomplish a lot with a year off, things that would be far out of your reach otherwise," says Magenau, who now works as an executive at an education company. "For those who don't take the year off, the time that passes is a blink of an eye. I asked a friend to tell me what happened while I was away and all he could remember about the year was who won the Super Bowl."

Men who work hard in their careers often make the mistake of thinking they would be happy if they had a year just to kick back. After working long hours at an Internet start-up, Alex Sheshunoff's first notion for his year off was to collect 40 books (20 recommended by his smartest friends and 20 classics that he was embarrassed not to have read in college), haul them to an underpopulated Pacific island, situate himself under a palm tree, and pour great literature into his head like so many margaritas. His master plan barely survived the first 150 pages of 'War and Peace.'

Time for plan B. "I learned that you don't just exist in paradise," he says. "Paradise is of your own making." He e-mailed friends who were also itching for a new venture, negotiated a 20-year lease on a plot of land on an island near Palau, and set about building their island dream house. From the beginning, the project was pushing the edge of his skill set – a goal worthy of a year off. Sheshunoff and his team are currently finishing the construction, working harder then they ever have at their day jobs.

"I don't mean to sound like Tony Robbins, but the ideal life is something you create for yourself, not something you drift into," he says. "Momentum is a powerful force in your life, and sometimes it can only be overcome with the sort of hope and arrogance it takes to quit your job and buy a one-way ticket to another country."

A year off can allow you to take an idea to an extreme. At 45, Al Hamlin quit his computer programming job in Cypress, California, to move to Boston and become the ultimate sports fan. He bought just-steps-from-the-hardwood season tickets to the Celtics (around $9,000), face-against-the-glass season tickets to the Bruins ($6,500), and between-home-and-first-base season tickets at Fenway ($11,000). Including living expenses, the year cost him nearly $100,000. "If you are going to take a year off to dive into something you love, you should make it as special as you can," he says.

John Pollack was grinding out speeches for former House Democratic whip David Bonior when he realized he needed a break. Since childhood he had collected wine corks, and at some point he reasoned that because corks float, he should build a boat with them. So he did. Pollack constructed a 22-foot-long cross between Kon-Tiki and a Viking longboat consisting of 165,321 corks held together by approximately 15,000 rubber bands. "If you take a year off you should ask yourself: What would I do if there was no one to stop me from following my individual passion?" says Pollack, who chronicled the experience in his book, 'Cork Boat: A True Story of the Unlikeliest Boat Ever Built'. "The cork boat wasn't reasonable, it wasn't practical, and in terms of its chances of success it wasn't even likely. To take a year away from your career or your life requires that you think big." His final triumph was sailing his 2,100-pound obsession down the Douro River in Portugal, the world's leading cork producer.

Scott Mandrell knows something about being obsessed. "Life is short, and a year off is even shorter, so if you've got an idea, you've got to go with it," he says. The 39-year-old history buff did exactly that. Mandrell is currently taking time off from his job as a middle school teacher in suburban St. Louis to play the role of Meriwether Lewis while painstakingly recreating Lewis and Clark's journey across the continent. Mandrell's crazy quest, in short, is to recreate another man's crazy quest. "We used to be a nation of men with harebrained ideas who would then go make them happen," he says. "Take a year off for your nation. We've got to fight against becoming meek."

It pays to plan ahead, but a year off rarely goes as planned. According to sabbatical coach Clive Prout, it's important to hit a balance between having a goal for your year off and not sticking too rigidly to any preconceived notions. "On one of my own breaks I met a guy who was taking a sabbatical while hiking through India," Prout says. "He knew exactly where he was going to travel and exactly what he was going to do at the end of his year. I thought, what's the point of taking a year off if you know exactly where it's going to lead you?" Like any other adventure, the potential benefits come in direct proportion to the risk it entails.

"At some point you'll be faced with an opportunity that will challenge your plans," says Ted Rheingold, founder of dogster.com (an online community for dogs and the people who love them). At 28, he stepped away from a fast-track Web development job to travel through Asia and the Middle East. "There's a boat that goes upriver to someplace you've never heard of, and it only leaves once a month, and you have an hour to decide. You should get on that boat."

Like Rheingold, most men who make successes of their year off quit their jobs without another one waiting for them. Others, like sales whiz Matt Green, return to their current careers re-energized. Every four years or so Green would quit his job in enterprise software sales in the Bay Area to take an extended break to ride bikes, as well as spend more time with his family. Green owns bikes for a reason: to use them, despite the occasional hazards. He was twice helicoptered off of racetracks after "dismounting" one of his superbikes at upward of 90 miles per hour.

He not only lived to bike another day, but each time Green came back into the working world he also managed to move up the ladder a couple of rungs. By the time he retired, in his early 40s, he was president of worldwide sales at BEA Systems, one of the most successful software companies in history.

"When I came back to work after a break, I found that I had a more realistic, pragmatic view of how to accomplish a goal like hitting the quarterly numbers," says Green. As a result, senior executives began to acknowledge his opinion on a new level. "I gained a maturity and perspective that went beyond the simple requirements of the job."

"If you do something impressive with your year off, you'll never have to hide the time on your resume," says sabbatical coach Prout. "No one is going to be impressed if you just kicked around on a beach, but if you've taken on a challenging project and learned something, future employers will see it as a plus."

Travel writer John Flinn and his wife celebrated their 30th birthdays while on a year-off trip around the world, traveling through Nepal, Kenya, and Egypt. Four years later they set out again. Flinn leveraged his two leaves of absence when he nabbed the coveted job of travel editor at the San Francisco Chronicle. "I have – let's face it – one of the best jobs around, and I owe it entirely to the two years I spent bumming around the globe," he says.

At 37, Kevin McKeown took a break from his life as a freelance translator in Vancouver after the failure of a seven-year marriage. He signed on to crew a three-masted barque sailing from Nova Scotia to the Virgin Islands, then through the Panama Canal to Polynesia and the Cook Islands. The skills he learned while living the life of an 18th-century sailor – maintaining rope, mending the sails, swabbing the deck – are invaluable, if not obviously transferable to most modern-day careers. "When you integrate yourself back into your old life, you bring back a sense of resourcefulness," says McKeown. "I became much more pragmatic about everything from my car breaking down to my business. You look at a problem and say, 'Okay, what has to be done to solve this?'"

Before he left McKeown was disenchanted with work and relationships; now back less than a year after an additional jaunt through Southeast Asia, his business is doing better than ever, he has plans to buy a house with his new girlfriend, and a child is on the way. Life, a year later, is good.

A year off is a chance to change yourself, but it's also an opportunity to change the world. Aaron Frank was a 27-year-old lawyer living in Atlanta when he packed his car and headed west with no destination or idea of what he was going to do. "All I knew was that putting on that suit every morning didn't feel like me," he remembers. "I had a lot of momentum in my career, but I began to feel like my routine was a thief stealing my life away one day at a time."

Frank took a few months and just listened to his gut. When he reached San Francisco, he decided to volunteer at a few environmental organizations – a cause he cared about deeply since interning with the Environmental Protection Agency during law school. One day while working with the Marine Mammal Center in Sausalito, California, he set out with a team to rescue a sea lion that had become entrapped in a gill net. "There was nothing more real than the physical challenge of working with a wild animal in danger," says Frank. "It had been a long time since I worked at something I was excited to get up and do again the next day."

Instead of going back to Atlanta, Frank moved to Malibu, where he cofounded the California Wildlife Center, a nonprofit that has responded to nearly 4,000 wildlife emergencies around the state. "You aren't going to see what you truly want to do in your life sitting behind a desk," Frank advises. "If all you know is that your life is leading you somewhere you don't want to go, you may need to take a leap of faith and walk away before you've figured out what you're going to do next."

At 26, Steve Rosenthal quit his job as an engineer for AT&T in New York and bought a one-way ticket to Nepal. His travels took him through Asia, the Middle East, and Africa. One week out of that year stood out as the most memorable. In a small village in Kenya, he met up with a friend who was in the Peace Corps and volunteered to help construct a medical clinic.

"For that week I was treated as a co-worker and as part of the community," says Rosenthal. "I was no longer the tourist walking through the marketplace with a big dollar sign on my back." Rosenthal was so taken with that experience that during his time in India he started Cross-Cultural Solutions, an organization he now runs from the States that has since placed 7,000 volunteers with short- and medium-term volunteer positions overseas.