In the Stone Age of American sports, when basketball still had a set shot and ballplayers wore baggy pants and metal spikes, athletes would introduce you to their lackeys by saying, "This is my childhood buddy." A decade ago, they would say, "This is my driver."

Today? "This is my pilot."

Private planes have become the sports world's latest must-have travel accessory. They are no longer just the indulgence of a handful of team owners with enough swag to buy, maintain, and house their aircraft. These days, squadrons of business planes fly athletes, teams, and league executives from arena to arena-and from golf course to golf course.

The increasingly customized world of private aviation has been likened to a Savile Row suit: a bespoke service tailored to the frequent flier's lifestyle. The 2008 ready-to-fly selection includes charters, aircraft-management services, and fractional schemes that—for a fee (paid in advance)—enable you to share the cost of a jet.

With commercial airport security precautions so onerous, no travel option is more suited to the harried, seat-of-the-pants existence of the professional athlete than the jet card, a kind of prepaid, reloadable debit card that allows travelers access to private planes without the burden of ownership. "Athletes may like to sign long-term contracts with their teams," says Jesse Itzler, co-founder of Marquis Jets, a for-hire company based in New York City. "But they don't like making long-term commitments for anything else."

The jet card offers athletes convenience, privacy, luxury, flexibility, and a bit of elitism. "It's a legalized drug, it's so addictive," Itzler says. His Marquis Jet Card represents a sublease of a share in the 740-plane fleet of Warren Buffett's NetJets, which controls 48 percent of the fractional market.

Each card provides flying time in 25-hour increments. Hours used are deducted from the card's balance after each trip. The leases vary in price according to the class of jet-from $126,900 for a seven-passenger Cessna Citation V Ultra to $349,900 for a Gulfstream 450, a 14-seater.

"To a lot of big-name athletes, $126,900 is pocket change," says Dennis Baker of Flight Options, a Cleveland carrier that offers the JetPass Ultimate Travel card.

Since its arrival in 2002, Marquis has been the jet-card industry's Air Jordan—which may be why the retired Chicago Bulls guard is a Marquis client. About 250 of Itzler's 4,000 customers are athletes.

"I'm on the road so much that time is of the essence," says Indy car driver Danica Patrick, who ran through four Marquis cards last year. "The card allows me to create my own flight schedule and fly in and out of small, regional airports close to racetracks. It's the only way I can buy time without delays."

The Marquis hoops roster would fill out an N.B.A. all-star team: Mike Bibby, LeBron James, Jason Kidd, Tracy McGrady, Dwayne Wade. Shaquille O'Neal used his jet card so often that he wound up buying his own plane. "LeBron and Tracy and Shaq can't walk though a commercial airport without getting mobbed," Itzler says. Marquis also has exclusive partnerships with the New Jersey Nets, New York Mets, and Boston Red Sox.

Lately, though, a bunch of startups and upstarts are luring athletes with a slew of innovations, from variable-pricing plans to elimination of the so-called deadhead charge, a ferry fee for an empty return flight after a one-way trip to a foreign country.

Flight Options is the Avis of the jet-card set, with about 25 percent of the trade. "Our membership grew 150 percent last year, just as it did in 2006," says corporate vice president Patrick Gallagher. "We now have N.F.L. players, major-league team owners, pro golfers, broadcasters, and auto-racing people." For reasons of confidentiality, Gallagher says, he won't divulge any of their names.

The operation has chipped away at Marquis by offering cut-rate roundtrips, abolishing blackout dates, and allowing clients to chose among three cabin types, depending on their needs or whims. A ballplayer might go with a light-cabin aircraft if he has invited his spouse or lover (or both), or a wide-body if his entourage is coming along. In contrast, Marquis cardholders fly on the jet model they paid for.

The unused balance on the Flight Options card has no expiration date and is fully refundable. Unused hours on a Marquis card run out after a year. Itzler insists that refunds are just another way to game the system. "If customers are demanding their money back," he says, "how good can you be?"

He likewise dismisses Flight Options' off-peak discounts, which allow a customer who flies on a Saturday to save up to 30 percent over Monday and Friday, when traffic is heaviest. "Golfers shouldn't worry about flying on Saturdays," cracks high-ranking pro Jim Furyk, a Marquis veteran who is paid to wear the company logo on his cap. "If you fly on Saturday, you've missed the cut and lost a lot of money."

Cut victims, take note: Flights Options requires only four hours' advance notice. With Marquis, you need at least 10.

Golf, of course, is the sport that's most synonymous with private jets. Arnold Palmer may have popularized this privileged mode of travel when he first flew solo in a Cessna 172 a half-century ago, but it was a journeyman golfer named Johnny Bulla who became the first athlete to buy a jet.

Bulla acquired a C-47 in the late 1940s and converted it to a DC-3. For a small fee, the former Eastern Airlines pilot taxied his fellow pros to tour events, thus becoming the first jet provider to cater to athletes.

The 78-year-old Palmer no longer has his own army, but pro golf does have an air force. In January 2007, Sentient Jet Membership signed a four-year marketing deal with the PGA Tour. The Massachusetts charter broker, which introduced the jet card in 1999, counts dozens of golfers as customers.

Sentient is a pay-as-you-go club with dues between $100,000 and $250,000. As with Flight Options, membership entitles you to three jet types, each with a different hourly rate.

Roundtrips on light aircraft start at $2,600, a yield of about 38 hours of airtime per $100,000. Sentient's latest in-your-face move against Marquis came in the form of its Preferred Plus Card, which slices 6 percent off hourly rates for those who agree to spend $150,000 a year on flights.
    
All this aerial warfare has Itzler saying, "Bring it! When you're dealing with world-class athletes, you expect a good game. I love head-to-head rivalries." In fact, Marquis was born of one.

The company was annealed—diamondlike—under the crushing pressure of athletic competition. One day about a dozen years ago, Itzler, now 39, was pitted against a fellow Long Islander named Kenny Dichter in an exceedingly physical pickup basketball game on the Manhattan's Upper East Side. The lean, scruffy Itzler had made a name for himself—albeit a small one—as a rap artist going by the name Jesse Jaymes.

The young rapper had crashed the Billboard Hot 100 in 1991 with the ballad "Shake It (Like a White Girl)" on his album Thirty Footer in Your Face. While trying to escape a fate as a one-hit wonder, he wrote "Go New York Go!," a rally rap for the New York Knicks. The Knicks rarely go these days, but the song is still played at Madison Square Garden.

The stout, immaculately groomed Dichter sold "attitude" T-shirts for a living (the biggest seller: "Why Work?"). Together, they came up with an idea for a business that combined music and sports and called it Alphabet City Records.

With Itzler writing the lyrics and Dichter the checks, the company produced music compilations for colleges, pro teams, and leagues. In 1998, Alphabet City was bought out by SFX, the sports promotion and talent agency. "We had sold it after two years for $10 million," Itzler says. "Not bad, considering we were 27 years old when we started."

They gained entrée to private jets through SFX. After a charter flight to the 2000 Super Bowl in Atlanta, Dichter told Itzler, "We're in the wrong business. Private jets are the future."

Dichter thought back to a wildly successful marketing gimmick he had conceived at the University of Wisconsin: a prepaid card for sports tickets. Then he remembered NetJets. A lot of his friends were interested in private planes, but they were turned off by the constant care and feeding that fractional ownership involved: the sizable up-front acquisition costs, the monthly management fee, the 50-hour-a-year minimum. "Why not just rent one?" Dichter asked.

He and Itzler powwowed with Richard Santulli, the NetJets founder and chairman. "An athlete understands 25 hours," Itzler said. "If he's flying from New York to Miami, that's two hours. He's got 23 left."

Santulli listened with the weary, seen-it-all expression common to homicide detectives and White House correspondents. "I appreciate your time," he told them, "but we're not interested."

A second meeting was arranged. This time, the budding entrepreneurs brought along a couple of pals to show their access to rich, young athletes and entertainers: onetime New York Giants linebacker Carl Banks and Jam Master Jay of Run-DMC. Santulli listened some more and said, "You guys are crazy if you think I'll go for this. Don't call me again. Don't come back. Ever."

On the way out of the NetJets compound, vice chairman Jim Jacobs told Dichter and Itzler, "Now we're getting somewhere."

Itzler said, "But that's twice he has thrown us out of his office in eight minutes."

Jacobs said, "No one gets eight minutes."

The pair's persistence paid off. After three more meetings, Santulli gave in and cleared the venture for takeoff. He figured that Marquis would make a splendid farm team for NetJets. And he was right.

Ten percent of Marquis' customers (including New York Yankees shortstop Derek Jeter and Atlanta Braves pitcher Tom Glavine) have graduated to NetJets fractional shares. And some less peripatetic NetJetters (Kidd) have dialed down to Marquis.

To Itzler, passenger load is the biggest difference between sports figures and other corporate-jet-card holders. "Athletes' planes are almost always full, which is fairly atypical," he says. They're far more likely than hedge fund C.E.O.'s to arrive at the gate with a barber, a manicurist, a trainer, a masseuse, and a psychic. "Jet time is now currency," Itzler says. "If one of our ballplayers invites eight teammates to fly with him, we quickly become locker-room talk. If Jeter is flying with us, A-Rod is going know about it."

On an hourly basis, a Marquis flight is about 10 percent more expensive than a NetJets one. "We're like a 16-ounce bottle of soda," Itzler says. "In comparison, you pay a little more than you would for 32 ounces. Athletes with Marquis cards don't need the bigger bottle."

Ultimately, an athlete's choice of jet card may come down to liking a model of plane. Fans of the Gulfstream 400 fly Marquis. Embraer Legacy 600 aficionados stick with Flight Options. If you've got a Learjet jones, buy a 25-jet card from FlexJet, a Texas outfit owned by Bombardier.
 
Ever since FractionAir was permanently grounded by bankruptcy in 2006, the fractional-jet-ownership industry—plagued by chronic maintenance problems and too much downtime—has idled on the runway. Revenue growth in 2007 was around 2 percent. But jet cards are soaring, and operators continue to launch sky-breaking membership packages. "We've been doing this for eight years, and we're only in the second inning," Itzler insists. "For athletes, it's definitely the first inning."