By Peter Savodnik, Bloomberg

The first time Ben Jenkins met Billy Gibbons, the guitarist and lead singer for the rock band ZZ Top, they sat in Jenkins’ 1958 Airstream trailer in the parking lot of the Four Seasons Hotel outside Dallas.

“The meeting was supposed to be at the hotel bar, but once he heard I had the trailer in tow, he commandeered a hotel golf cart and we went out to do the meeting at the trailer,” says Jenkins, the 39-year-old owner of the Texas design company OneFastBuffalo, whom Gibbons had hired to help launch an online store. Jenkins bought the renovated trailer four years ago. It serves as a mobile office and, occasionally, his second home.

For adventurous entrepreneurs, architects, graphic designers, engineers, and salespeople, the office is wherever they choose to park. These professionals are “location independent,” in the words of Airstream owner Sharon Pieniak, a 41-year-old designer and photographer.

Pieniak doubts she’ll ever go back to working in a regular office. “I’m a freedom junkie,” she says, “though I might decide to have a home base to return to every now and then, where I can keep things I collect from traveling.” Pieniak plans to spend the fall working with clients in Napa.

Much of the mobile office buzz stems from the weakened economy. Airstreams cost from $50,000 to $60,000; for an independent contractor on a budget with a demanding travel schedule, that makes them a tantalizing alternative to renting expensive office space by the square foot, says Wally Hofmann, co-owner of Hofmann Architecture in Santa Barbara, which specializes in the renovation of Airstream interiors. With 12 trailers in production, Hofmann says he’s operating at peak capacity and receives more than 50 calls a month.

Sales of brand-new Airstreams are up, too. Over the past 12 to 18 months, says Airstream Chief Executive Officer Bob Wheeler, “we have seen a significant increase in the amount of people who are utilizing their Airstream for both professional and recreational use.”

An artifact from the Depression era, the Airstream maintains a cult-like following for its distinctive, Deco design. The sizable interiors easily convert into modern work spaces. With Hofmann’s upgrades, such amenities as air conditioning, security, and track lighting can be controlled with an iPad. Even the color scheme has been rethought to be more office-friendly. “The original Airstream did a lot of dark brown, vinyl-covered surfaces,” Hofmann says. “That really stops your eye. Light colors tend to open it up and let the person decorate the space to their personality.”

The redesigned trailers are especially popular among women. Because 75 percent of his customers are female, says Hofmann, he’s nicknamed the Airstream the “Mom cave.” He says the trailers are ideal for a working mother running a boutique consulting shop while also juggling responsibilities at home. When not using her work space to conduct business on the road, she commutes to the driveway.