When the European Union deregulated the skies over Europe about 5 years ago, a handful of entrepreneurs began studying Southwest Airline's business model -- then they set out to copy it. Now, nearly a dozen airlines that most Americans don't know about are making it drastically cheaper to zip from, say, London to Rome. But if you live in the U.S., the trick is finding those airlines, learning where they fly, and buying a ticket. You won't find them on U.S.-based travel Web sites, and travel agents won't be of much help, either.

But they're worth looking for because you can fly between London and Paris for about $50 each way, or between London and Barcelona for $70. If there's a sale on, as there was when I was in London recently, you might be able to fly from London to Dublin for $13 one way. That's less than it costs to take a train from downtown London to the airport!

The largest discount airlines are Ryanair, easyJet, go, Virgin Express and buzz. A couple of them are stepchildren of larger, better-known airlines, such as British Airways or KLM. But you won't find them on the big airlines' Web sites.

Meanwhile, here's what you should know: most of these airlines are no frills -- you may even have to pay for a can of soda on board; most offer e-tickets only and open seating; most do not have baggage agreements with other airlines, so if you're connecting flights, you're going to have to claim your bags and re-check them; and, most depart from smaller airports, such as Luton or Stansted near London.

Is there a European Web site that compares the fares of all European airlines? I'll list two, but neither is really comprehensive. One called easyvalue.com compares prices on discount flights from the United Kingdom to the rest of Europe. But that doesn't help you if you want to fly from, say, Milan to Barcelona. It's best to know which airlines serve which cities, and then visit their Web site or call. And, no, none of the airlines have U.S.-based toll-free numbers. Again, I'll post those overseas numbers, along with the Web addresses below. Phone reservation agents generally speak English, but some discount airlines don't man their phone lines around the clock.

Now, there's a second way to fly around Europe for less, but only if you're flying from the U.S. with a major foreign airline. Several offer intra-Europe deals to passengers as long as they buy tickets before -- and only before -- they leave North America. Air France, for example, sells a minimum of three flight segments anywhere within Europe for $120 each. British Airways prices its by distance. But you must call the airlines -- I could find no mention of the deals on those airlines' Web sites. Again, you must fly the foreign carrier across the Atlantic and book your intra-Europe flight coupons before beginning your trip overseas.

Cheap European flights -- they're a bargain if you know where to look. From The Savvy Traveler, I'm Rudy Maxa for Marketplace.

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