In Silicon Valley, they are known as nerd birds.
They jet between the office towers and congested corporate campuses of Northern California and the office towers and congested corporate campuses of such tech hubs as Boston, Seattle and Austin, Texas.
They are filled with passengers toting laptops, tapping on handheld computers and, where regulations permit, jabbering on cell phones.
And in recent months -- despite all the news about the tech stock market taking a nosedive -- the selection of flights patronized by tech-industry travelers has been quietly expanding.
At California's San Jose International Airport -- self-dubbed "The Gateway to Silicon Valley" -- carriers have recently added direct flights to several cities with high concentrations of technology companies. Jim Peterson, deputy director of airport business development, says the airlines are expanding routes largely to cash in on the high volume of business travel.
"The idea that Internet is going to replace travel, that's a myth. It's the opposite," says Peterson, who notes that the volume of passenger traffic has risen in the past year.
In January, the most recent month for which data is available, 1.2 million seats were filled entering or leaving the airport, up 17 percent from the same period last year. About 64 percent of passengers are business travelers.
Airlines are competing heavily for a slice of that traffic. In the last six months, carriers have introduced direct routes from San Jose to Ottawa and Raleigh-Durham, N.C., and added new flights to New York City, among other destinations. Starting in April, new flights will be connecting Silicon Valley to Taipei and Paris, with a new flight to Calgary starting in June.
Airline executives have a simple explanation for why carriers prefer customers who travel for work rather than pleasure. It's all in the economics.
"Business travelers are desirable. They tend to pay more," said Bob Ferguson, CEO of Midway Airlines, which recently started offering daily nonstop flights between Raleigh-Durham and San Jose. "They tend to buy walk-up fares which are more expensive than things purchased in advance."
Midway has taken some steps to appeal to the deep-pocketed traveling geek. In the Raleigh-to-San Jose route, the airline added four first-class seats. It also passes out an updated style of laptop-size DVD players to keep passengers entertained.
Tech industry workers were a key group Midway was targeting when it started planning the flights last spring. The airport serves North Carolina's Research Triangle region, which is home to a large concentration of technology firms.
Even so, the seats aren't selling out. The new flights are filled to only about 41 percent of capacity, Ferguson said, adding that he expects volume to pick up in the spring and summer.
Officials at both Midway and American said they shy away from using the term "nerd bird" to refer to flights to and from Silicon Valley. However, they're well aware the term is a popular unofficial nickname.
According to the Silicon Valley Slang Page, an online lexicon of geek terminology, the phrase "nerd bird" originally referred to a single flight route populated by techies. It defines nerd bird as:
"Any weekday direct airline flight between Austin, Texas, and San Jose, California. There are many engineers and technical types regularly on this flight since there are so many tech developments in both cities. It is also known that a good amount of job seeking and rumor milling occurs on this flight."
While the slang dictionary lauds the nerd birds for their rumor-gathering potential, the flights' passengers also have a reputation for being on the secretive side. Loud conversations about the latest strategic meeting can be a dangerous thing, since a competitor could easily be lurking behind a laptop screen across the next aisle.
It's not only the passengers that add a techie element to Silicon Valley flights, said Mark Slitt, a spokesman for American Airlines. From international flights in particular, airlines generate a nice chunk of revenue from the boxes of tech gear stowed in the belly of the plane.
"Cherries, asparagus and electronics are the three biggest things," said Slitt, describing the cargo in the airline's decade-old route between San Jose and Tokyo.
He expects the load to contain even more gadgetry and device components on the new route from Silicon Valley to Taipei.
Even so, the crowd aboard the plane won't be limited to pocket-protector-clad geeks. On the Taipei flight, bookings come from a balanced mix of vacation and business travelers, said David Chien, San Jose office manager for C&H International, an airline ticket consolidator.
If the tech industry's economic performance continues the way it's been going, carriers will need to drum up all the vacation traffic they can get. Despite the rollout of new routes, the past several months have been a tough period for many U.S. airlines that are seeing declines in business travel.
Northwest Airlines warned Wednesday that its loss for the first quarter of the year would be larger than expected, due to declines in corporate travel. The news came on the heels of profit warnings from Delta Airlines and U.S. Airways Group.
And fears of a slowdown in tech travel were triggered by an earnings warning last week from one of Silicon Valley's largest employers, Cisco Systems. In addition to eliminating thousands of jobs, the company said it would engage in "aggressive cost cutting" in its travel budget to shave expenses.
Optimists like San Jose Airport's Peterson aren't expecting to see much of a slowdown in Silicon Valley air traffic. It's been a year since the technology stock market downturn began, and for most of that time, travel volume has been on the rise.
Of course, some of that traffic could be laid-off tech workers flying in for job interviews.