The office is awfully quiet these days.

That’s because half of American workers are toiling away offsite at least part of the time.

They’re working from home, from a hotel room or at a customer site. Where they are varies. Where you won’t find them is behind their desk down the hall.

For workers, that means more freedom, less traffic and a better shot at actually achieving that allusive work/life balance.

For the IT department, however, it means more planning, extending the network and increasing security.

Virtual workers mean real headaches for IT. And brace yourselves, because over the next several years, millions more will forego a desk for a corner of the kitchen table and the power lunch for picking their kids up after school.

According to the International Teleworkers Association Council (ITAC), there are 28 million teleworkers in the United States.

And take note that a teleworker is not exactly a telecommuter. Teleworker is a broader term, including people who work outside the traditional workplace a few days out of the week, whereas a telecommuter is seen as someone who works remotely fulltime.

Regardless of the specifics of the newly coined definitions, working offsite is on the rise – in a big way.

The ITAC predicts that the number of teleworkers in the U.S. will increase by 6 million a year for the next three years.

The workforce has officially gone remote.

Telecommuting or teleworking is no longer an exotic or controversial concept.

Today, the fuzzy slipper crowd rules — you know, the folks with more pairs of pajamas than business suits and where a coffee break means brewing a pot and sipping it on the deck instead of dropping coins into a machine in the lunch room.

“As our online tools have gotten better, it’s often more productive not to be in the office,” says Pam Stanford, director of Dynamic Workplaces Solutions at IBM, which has seen 80,000, or a quarter of its workforce, go remote.

“I get more work done when I’m telecommuting. If I have a 2 o’clock meeting, I work until 1:59 and then call in to the meeting.

At a physical location, you get up, get a coffee, grab your Think Pad and fight over the plug-ins in the meeting room. There’s a lot of air time you can compress right out of your day.”

And IBM isn’t just getting more work out of Stanford, whose entire team is made up of telecommuters.

The high-tech giant is saving a lot of money on all its teleworkers. IBM reports that workers going remote saves the company more than $1 billion over a 10-year span.

“It’s much more cost effective,” says Mike Bell, vice president and research director of the Workforce/Workplace Research Group at the industry analyst firm, Gartner Group.

If they can give up their assigned workstations, that saves real estate money... If you can promote desk sharing back at the ranch, in combination with remote working, you can cut your costs per person anywhere from a half to a third.”

Bell and his colleagues predict that by 2006, the fundamental work unit will be a virtual team.

And that makes financial sense when you figure that the average cost of an in-office seat is $24,000, according to Bell.

Compare that to the $6,000 to $8,000 price tag for a remote worker. The cost difference is largely due to the enormous price of corporate real estate.

“The trend for companies is to shrink their real estate footprint and designate offices as shared space,” says Bell.

“Have folks work in a network of places – from their homes, the road, a hotel and a shared desk in the office.”

And companies are reaping the savings.

Sun Microsystems Inc. reports an annual savings of $75 million. AT&T; does even better, reporting yearly savings of $200 million.

Proctor & Gamble pockets $100 million thanks to its remote workers.

While the teleworking phenomenon may be benefiting the corporate bottom line, it isn’t so easy on the IT department, which has to enable these millions of workers to be just as efficient and just as connected as if they were working right down the hall.

Tim Kane, president of the ITAC and CEO of Kinetic Workplace, a company that helps customers implement offsite work programs, says getting the right technology in place is the biggest obstacle to successfully moving workers offsite.

“One of the main inhibitors to telework has been speed and with broadband that comes off the table,” says Kane, who says executives see teleworking as a tool to compete for and retain talent.

“If I was an IT director, I’d look at these drivers and sit down and take a hard look at having a network that goes beyond the walls of the organization itself.”

And Kane says that means plotting out extra security, erecting more VPNs, and making company information, like vacation time and work policies, available online.

It also means making sure that every teleworker has three or four means of communication – email, instant messaging, telephone lines, online meeting software and collaboration software.

“If the IT department hasn’t thought through these technologies, then they’re behind the curve,” says Gartner’s Bell.

Do they have necessary remote access and security? Can employees call in through VPNs from hotels or from home? With more managers and professionals moving from desktops to laptops, have you thought through support issues, like asset management and increased security?

Do you have 24/7 support capability so when a problem hits for someone on the road, they’re not hearing that there won’t be anyone in support until 9 the next morning?”

IBM’s Stanford says IT leaders need to sit down and plot out a plan for handling what can easily become a major drain on a department already plagued by budget cuts and layoffs.

“It’s definitely tough on IT,” she says. “Someone just can’t declare they’re going to start telecommuting and take their computer and go home. You have to have a plan.”