Tony Drockton, who owns a luxury handbag company in Southern California, used to take the overnight flight to New York, rather than waste business hours out of touch.

But now, his flight time is his work time as airlines increasingly offer Wi-Fi connections on their planes.

"I need to stay connected so people don't realize where I am," said Drockton, who now travels with a laptop, smartphone and over-the-ears headphones. "It allows me to fly during business hours and not miss any day."

As to those travelers who enjoyed a few hours of being out of touch with the office, those days may be ending. Before Wi-Fi, "you had an excuse not to be in touch if you didn't want to be," said Henry H. Harteveldt, co-founder of Atmosphere Research Group, an airline and travel industry analyst in San Francisco. "The one last bastion of being off the grid has been taken away."

And as airlines race to create connectivity on international flights through satellite Wi-Fi, the ability to stay online in the skies will only increase, experts say.

"Passengers have an expectation of ubiquitous connectivity in their lives, especially younger travelers," Harteveldt said. "Walking on the street, in coffee shops, and it frustrates them when they get on a plane and they are told they're offline. The traveler wants to have control over when they go online."

Others echoed his analysis. "People want to be connected 24/7," said Jonathan Kletzel, a transportation and logistics analyst at PWC. "It's a question of whether airlines are getting ahead of the curve or not."

For now, technology use in the sky remains lower than on other modes of transportation, said Joseph P. Schwieterman, director of the Chaddick Institute for Metropolitan Development at DePaul University.

Even so, Wi-Fi Internet access has expanded to 153 million passengers in 2011 from 153,000 in 2009, according to Gogo Wireless, a Wi-Fi provider for airlines.

According to a report this year from the Chaddick Institute, the percentage of air travelers using technology at "random selected points" on a flight was 28.4 percent in 2011, up from 23.2 percent in 2010 and 17.6 percent in 2009.

The report found that more travelers were bringing their own devices, including tablets and e-readers, with them on planes. One in 12 airline passengers is now using a tablet, and that number continues to grow. Tablets account for almost 30 percent of all technology use on commercial flights, and that share is also likely to grow. The use of tablets and technology, in general, tends to be "significantly higher on business-oriented flights," the report said.

This leaves more than 70 percent of passengers who are not using a device, and may be using the airlines' in-flight entertainment options, Schwieterman said.

Wi-Fi stretches back commercially four to five years. Now, nine commercial airlines have Wi-Fi air-to-ground service on all or some of their domestic flights. The fees depend on the length of the flight, and tend to range from $1.95 to $19 or more, according to Gogo.

Travelers are using the connection to do more than send email. What travelers want, especially business travelers, are many methods to stay productive and entertained while en route to their destination, airline experts said. They may use their own laptops or tablets as well as the in-flight entertainment system.

Drockton, for example, said he uses email, air-to-ground videoconferencing, the airline's instant messenger system and the entertainment system in the seat back in front of him when he is flying. He said he relies on the power outlet under his seat to keep his laptop charged. "I plug in before they even close the door," he said. "I'm already working before they take off."

Until a few years ago, the airlines were a "technology wasteland," Schwieterman said. Now, most major airlines, even those that were late to Wi-Fi, have committed to partnering with one of the four major Wi-Fi providers. The airlines "want you to know that Wi-Fi is on the flight," he said. "They know they need it for brand positioning."

Still, Internet connectivity in flight has its shortcomings, though Harteveldt and other frequent fliers said they expected it to improve in its next generation. "If the Wi-Fi system is maxed out, it slows down," Harteveldt said. "You can log off and not be able to get back on, or be booted off the system."

Typically, the bandwidth of the Wi-Fi on a single-aisle plane like a Boeing 737 or an Airbus A-320 can handle 25 users at a time. If one traveler begins to download a large file, "the system slows to a crawl," he said.

Kevin P. Nichols, 39, director of content strategy for SapientNitro, said that had been his experience. "It's inconsistent, and you never know if it's going to work or not," he said.

Nichols said Wi-Fi and in-flight entertainment provided by the airlines were among the factors travelers now considered. "There are a lot of drivers in selecting an airline," he said. "It's people having access to what they want. We continually want to be plugged in."

As for the future of in-flight technology, Harteveldt said it depended on technological developments, travelers' preferences and airlines' budgets. The airlines tend to update cabins every five years. Harteveldt predicted that within 10 years, flights would be a "BYO entertainment" environment -- that is, bring your own.

Until then, travelers who want to stay productive and entertained en route to their business meetings are dependent on Wi-Fi.

Or, as Drockton put it: "It's just about convenience and connectivity. I need it to work."