By Elizabeth Woyke

updated 10:02 a.m. ET March 11, 2008

Beth Breidenbach calls it the "vulture hover."

It's a maneuver familiar to anyone looking to use a laptop in an airport—the circling, swooping dance to locate and secure access to wireless Internet (Wi-Fi) and power outlets.

Breidenbach, a Spokane, Wash.-based senior data architect for IBM Global Business Services, is on the road an average of 45 weeks a year. To cope, she's memorized plug locations in her favorite airports—she's found them by the main poles in the seating area in Denver International Airport; by the workstations at Chicago's O'Hare and New York's LaGuardia; still others near particular restaurants in Minneapolis, where she can grab a bite while charging her laptop and Palm handheld.

The seasoned traveler is doing less vulture hovering these days as airports ramp up their Wi-Fi service. "I tend to assume that Wi-Fi will be available in an airport until proven otherwise," Breidenbach says.

In an increasingly data-dense world, travelers will soon be able to surf the Web from the skies. Until then, however, the next best thing may be to fly out of Denver or Las Vegas: They represent two of fewer than 10 major airports around the world that offer free Wi-Fi Internet access throughout their public areas. That's landed them at the top of Forbes.com's first ranking of wired airports.

Atlanta's Hartsfield-Jackson International grabs the No. 1 slot. It doesn't have free Wi-Fi, but does boast airport-wide coverage with at least five major providers. Atlanta also got a boost from its sheer size—with nearly 85 million passengers per year, it's the busiest airport in the world.

More from Forbes.com Click below for more slide shows Gadgets that make business travel a snap America’s most wired cities Where to get off the grid in the world Where to get off the grid in the U.S. Great gadget expectations

Of course, most airports are wired to some extent, in spots such as their elite members' lounges or the in-house Starbucks. But to grab a spot on our list, an airport must offer broad Wi-Fi access to regular passengers—for free, or at a reasonable price.

To compile the list, we looked at the top 50 airports around the world, measured by passenger traffic. (The more passengers, the more Wi-Fi usage.) That knocked out some smaller airports with robust networks, including Albuquerque, N.M., and Sacramento, Calif.

We then rated airports based on three criteria: the breadth of Wi-Fi coverage, whether they charged for the service and how much, and how many providers they offered as options. Finally, we looked at the comfort and convenience factor. That included checking out whether the airport offered workstations, adequate seating and electrical outlets, as well as facilities like computer rooms and business centers for travelers looking to get online without their own laptops.

Those filters gave us a list of 48 airports—21 in the U.S. But since travelers regularly head across international boundaries, we capped the U.S. airports at nine—both to shorten the list and to make room for more overseas airports.

Travelers agree: Well-equipped terminals make a difference. A 2007 survey by SITA, a Geneva, Switzerland-based provider of IT and communications services for the air transport industry, found that 25 percent of passengers carry Wi-Fi-enabled laptops. Of that group, 42 percent associate a Wi-Fi connected terminal with a "pleasant trip."

A well-wired airport isn't just a boon for multi-tasking road warriors. As more people invest in smart phones and cellular data plans, airports are becoming increasingly important networking zones for leisure travelers, too.

Airport managers are heeding the calls for more data. Many airports are adding Wi-Fi. Some see it as a revenue source, but a growing number are making it free throughout all the terminals.

Denver International Airport has offered fee-based Wi-Fi since September 2002. Service provider AT&T originally charged $7.95 for a one-day pass Wi-Fi. Last November, the airport itself took over as operator, and began offering the service gratis to travelers.

"It was one of the things that kept coming up on complaint cards: 'Why isn't your Wi-Fi service free?'" says Jim Winston, the airport's telecom chief.

Usage has since shot up from around 600 connections a day to more than 4,500. "A lot of people just didn't bother before," says Winston.

To offset the cost, Denver started running ads. A 30-second video from companies including Ford Motor, Microsoft, Toyota and Charles Schwab greets users when they log on. Banner ads top the Internet sites they visit. Winston expects the ad revenue to match—and eventually exceed—the amount previously generated from the paid service.

MORE FROM BUSINESS TRAVEL

Business travel Section Front

The last all-premium airline may vanish No more dingy bars for road warriors Airline troubles mean a return to the past The incredible shrinking airlines The worst airline — ever As gas prices spike, Americans ride the rails FAA orders immediate inspection private jets Best restaurants for business meals Why are all-business-class airlines are failing? Safety tips for travelers' protections Business travel Section Front   Add Business travel headlines to your news reader: