A CLOSER CONTINENT.

When Kurt Wilson's pals told him they were throwing him a bachelor party in Vilnius, Lithuania, back in 2002, the British entrepreneur was less than thrilled. Aside from cheap beer, what could this grim former Soviet bloc city offer? Plenty, as it turned out. Wilson, now 32, fell so in love with Vilnius, with its friendly people and beautiful medieval old town, that he has since made it his second home.

A Brit commuting to Lithuania? A few years ago, such an idea would have been unthinkable. Now, thanks to airfare as low as $100 round-trip on Ryanair or its local competitor, Air Baltic, Wilson and his wife travel between London and Vilnius at least once a month. The couple owns two apartments in Vilnius. And Wilson, impressed with the skilled and inexpensive local workforce, opened a local office of Advansys, his Reading-based software development company. "When I first came here, my friends thought I was mad," he says. "Low-cost airlines are opening up places that used to be beyond most people's comfort zones."

Ryanair, easyJet, and nearly 40 other low-cost airlines across Europe are accomplishing what the politicians in the expanding European Union couldn't. Not until the discount airlines came on strong did millions of Europeans start to cross borders en masse for business and pleasure. Airlines last year logged more than 420 million passengers on intra-European flights, an increase of some 40% from five years ago. In the process, they've played a major role breaking down cultural barriers, revitalizing local economies, and opening up new business opportunities. "Bureaucrats in Brussels have been blathering on about European unity for ages," says Michael O'Leary, CEO of Dublin-based Ryanair. "But low-cost airlines are at the forefront of delivering it."

Jetting around Europe used to be a luxury. Now it's possible to crisscross the region for as little as $30 round-trip -- less than the fare on a taxi ride to the local airport. The British pop over to Budapest for budget root canals and cut-price nip-and-tucks. Irish property speculators fly to Estonia to bag a bargain. Latvian construction workers head to Dublin to cash in on that city's construction boom, while Polish doctors and nurses jet over to Britain to fill hospital shortages. "I've been to places I've never even heard of just because it's so cheap," says Dave Marsden, a 38-year-old dispatch manager at a Manchester printing company who recently spent a weekend in Santiago de Compostela in Spain.

The explosion in low-cost flights has given rise to a new group of Euro-commuters. For six years, Herman Bynke, a 34-year-old Swede who runs London-based Hela Ltd., a maker of ergonomic computer accessories, endured the stress and high cost of living in London. But when Ryanair began offering direct flights from London to Gothenburg, Bynke decided it was time to move back home. Now for $85 or less round-trip, he makes the three-hour door-to-door trip from his home in Sweden to his office in London biweekly. "I can spend more time with my family, save more money, and have a better quality of life," he says.

The trend originated in 1997 when Brussels deregulated the aviation industry, enabling discounters to get airborne. Ryanair was one of the first. The Irish carrier launched service from Britain to the Continent in 1997, keeping fares low by flying to smaller, out-of-the-way airports, a model pioneered by Southwest Airlines Co. in the U.S.

Today, Ryanair is Europe's leading discounter, flying 334 routes to 23 countries. The company is on course to log a 6% increase in pretax profit this year, to $409 million, on revenues of $2.1 billion, according to estimates from Switzerland's UBS. O'Leary's fleet of 105 Boeing 737s will ferry some 42 million passengers this year, more than British Airways. To fight back, BA, Air France, Lufthansa, and the other flag carriers have been slashing their own fares. The fare wars could set the stage for an industrywide European shakeout, but for now consumers are the big winners. In Sweden, for instance, the average international airfare fell from $160 in 2001 to $110 last year.