Hi boss! Remember me?

Job hopping is nothing new.

With the lycra-tight labor market, Americans seem to change jobs as often as Madon-na changes her hair color.

By some estimates, workers will switch jobs as many as seven times in their lifetime.

But a new trend is emerging on the job front: Workers are hopping back to their former employers - often for more money and a bigger title.

The workplace already has a name for them: boomerangers.

"These people are just like a boomerang: You throw it out there and it comes right back to where it came from," says Jeff Kaye of Kaye/Bassman International Corp. in Dallas, an affiliate of Management Recruiters International.

No doubt the maneuver is most prevalent in the high-tech world. But it's cutting across other industries as well.

Most boomerangers don't leave their employer with the intention of returning. It just happens.

Many return after learning their new job wasn't as good as they thought it would be. Others come back when their old boss leaves. Or they find out they can make more money.

There seems to be no time line to boomeranging, either. Some return after a few years, some a few months.

"It definitely is a growing trend across the industry," says Judy Wiens, manager of strategic sourcing at Motorola Inc. in Schaumburg, Ill.

Take Barbara Siegel, who joined Motorola as a systems tester back in 1991. When the company reorganized in 1997, she was moved to a department that did not suit her.

So Ms. Siegel left Motorola for a management job at US Robotics. She spent three years there and stayed on through the firm's merger with 3Com.

Shortly after that, however, her job felt stagnant. She began to look for work elsewhere and came across an opening at Motorola working with the people she had started out with. She applied and rejoined the company earlier this year.

Part of the appeal of returning to Motorola was the company's clear management track. "I know how Motorola's structure works," Siegel says. "I know how well they make those steps visible."

"No one asked me why I left and why I came back," she adds. "The philosophy here is that I invested six years here and they invested in training me."

For many companies, welcoming back ex-employees is something of a new philosophy.

In the not-so-distant past, once you left a company, you never looked back and neither did your employer.

In fact, most companies denied your very existence.

But with unemployment at record lows, businesses are warming up to workers who abandoned ship. Some have even dropped the name ex-employee in favor of "alumni."

Bain & Co., a Boston-based consulting firm, goes all out to keep in touch with its 2,000 alumni. It holds social events and sends out newsletters.

"If you have a good employee who decides to leave, many companies now embrace the idea of welcoming them back," says John Challenger of outplacement firm Challenger, Gray & Christmas in Chicago. "It's a product of the tight labor market."

Yet there's another side to boomeranging that companies often overlook - the impact it can have on the morale of workers already there.

Say a worker leaves for a competitor and then returns after just a few months or a year - getting a bump up in pay and a corner office.

The result: The rest of the office now contemplates a move to your largest competitor.

"It does send the message that the only way to get ahead is to leave and come back," says Sam Webber, a recruiter at Source EDP, a high-tech staffing firm in Boston. "You hate to say it, but I've seen it."