(MONEY Magazine) – You could just go to Paris. You could take your precious week or two of vacation, fly all the way across the Atlantic Ocean, park yourself in a hotel, eat at a different café and go to a different museum every day, shop and fly home. You'd have a wonderful time, no doubt. In fact, you could do the same in Rome or Stockholm or almost any other European city and have a lovely trip. But there's a new way to explore the Continent that includes much more of, well, the Continent: flying. Discount airlines have been appearing all over Europe—dozens have taken to the skies in the past two years, according to the Association of European Airlines (AEA). But don't think Southwest or JetBlue; European discounters make their American counterparts look like the Concorde when it comes to cheap fares, and these thrifty fliers are introducing Americans to itineraries (and small towns) previously available only to college kids who were willing to sleep on trains and live out of backpacks.

Why should kids have all the fun? And forget group tours that command you to be at the bus no later than 9 a.m. whether you've finished your pain au chocolat or not. Now you can put together your own elaborate itinerary. Would you like to catch the Royal Shakespeare Company and the Vienna Philharmonic during the same vacation? Or eat at Spain's El Bulli one evening and dine on fresh snapper in a Greek village the next? See the sun rise over the Cliffs of Dover and catch Stockholm's midnight sun in the same circadian period? The air fares that make this kind of romantic hopscotching possible are usually less than $75 and sometimes as low as a dollar—a lot less than coeds shell out for their Eurail passes. (Try one of the three trips we dreamed up, starting on this page.) Most flights are short. Book ahead or on the spot, depending on your appetite for adventure (some travelers have been known to show up at the airport, ask where the next plane is heading and hop on).

One last thing: You may have heard about the miserable shape the dollar is in right now, but that's all the more reason to do a jump-around-style trip. With flights this cheap, you'll be justly proud of yourself for seeing four countries in 10 days for less than it costs to take Amtrak from Boston to D.C. Plus, no one ever said on his deathbed, "Thank goodness I saved 87¢ on the dollar one year instead of seeing all the castles in Europe." Now get your vacation off the ground.

Who are these airlines? Europe has two major players: Ireland's Ryanair and Britain's easyJet, which, says the AEA, have carried more passengers than the next 10 competitors combined. But start-ups come from all corners of the European Union: The newest airlines include Poland's Centralwings and Italy's MyAir.

How does it work? First, get yourself across the Atlantic. Although most major European cities are served by at least one low-cost carrier, if hopping around Europe is your goal, consider flying first to a discounter hub like London or Berlin.

How low can fares go? "Fares are almost entirely demand-driven," says Edmond Rose, head European analyst at GCW Consulting, which specializes in the airline industry. "The first 10 people who book are going to get the cheapest fares, and then it will be marked up slightly." Scan ryanair.com and easyjet.com for booking information. The average fare on Ryanair is 42 euros (about $55), but when booking far in advance, you might see tickets for $1. (The airlines exact carriage taxes, which can total $25.) One recent pretax fare from Cork, Ireland to London: 0.01 euro.

0.01 euro? Is that a misprint? It is not. The strategy these airlines use is to try to fill every seat by offering low fares and then to make money selling and renting items onboard—a handheld digital media player for six euros, say. And everything is for sale: On easyJet, even the sickbags are emblazoned with paid ads. The airlines also save money by using smaller airports, where runways are less congested. Getting to and from can require a train or a taxi—London's Luton Airport, for example, is 30 miles north of the city and looks somewhat like a bus station.

Are they comfy? Another way the airlines tamp down prices is by stripping away onboard comforts—reclining seatbacks, magazine pouches, everything. You might not have that first-class feeling, but most flights around Europe are quick hops, and sacrificing a little comfort for an $8 cross-continental ticket can be a worthy trade-off. But the low-fare market is best described as Darwinian. One MONEY staffer was temporarily stranded in Barcelona when her airline, Volareweb, was shuttered mid-vacation. Rather than flying straight to Rome, she took a side trip through Brussels on an established discounter, Virgin Express. (Brussels, incidentally, turned out to be a blast.)

Are they safe? "These airlines have to conform to common safety standards throughout the EU," says Rose. Those are the same standards to which British Airways, Lufthansa and any airline that flies to the EU must adhere. "The standards are as good as anywhere in the world," says Michael Boyd, an airline consultant. "People who fund airline start-ups have to spend a lot of money, and they aren't going to fund fly-by-nights."

Five Castles, Five Different Centuries, One Cuckoo Clock: $694

10 Days, Four Countries, Several Glasses of Whisky, 50 Meatballs: $687

NOTE: All prices are as of January for March travel; all flights from New York are round trip.