Like a lot of folks these days, Mark and Deb Stutelberg were looking for ways to save money.

They found it at their fingertips. About a month ago, the Woodbury family dropped their home phone line, and now the couple and their three children make and receive all their calls on their cell phones.

"I wouldn't consider it a sacrifice at all," Mark Stutelberg, 52, said about dropping the land line. "It was really pretty painless."

A growing number of Americans are dropped their home phones in favor of using their cell phones as their lifelines to the world.

A recent government survey showed that more than one out of every six American households, 17.5 percent, had only wireless phones in the first half of 2008, more than double the percentage three years ago.

Such "cord cutting" is expected to accelerate as the economy goes from bad to worse.

"Both a home phone and a cell phone could become a luxury for some and lead to cord cutting in favor of a single-provider solution," predicted Forrester Research (NASDAQ:FORR) , a technology consultancy based in Cambridge, Mass.

Forrester expects the number of wireless-only households in the United States to grow from 20.7 million households last year to 32.9 million by 2013. That would mean that within five years, more than a quarter of all households in the country would rely solely on their mobile phones.

Most cord cutters are under age 30 and single, but the trend is spreading beyond the cell phone generation.

Nearly one in five, 19 percent, of adults between ages 30 and 44 were wireless-only last year, along with 9 percent of those 45 to 64 years old, according to a survey by the Centers for Disease Control and Prevention. The CDC keeps track of such things because it relies on phone surveys to gather information.

With more than 270 million wireless subscribers today in a nation of about 305 million people, according to industry figures, the cell phone has gone from being a luxury to a must-have.

"For us and for our children, the cell phones were more necessary than a land line because of the mobility -- you can call on your way to and from work or other places," said Stutelberg, a church administrator. "We never really considered getting rid of the cell phone."

It took a couple of weeks for Verizon (NYSE:VZC) (NYSE:VZ) Wireless (NYSE:VOD) to transfer their home phone number to one of the cell phones, Stutelberg said. Now, the family saves $40 a month and hasn't had any major problems.

"There was a little bit of an adjustment," he said, "because we've got to remember to have the phone on at home and on an audible ring."

Traditional phone companies don't like losing land-line customers but acknowledge the trend. Qwest Communications International (NYSE:Q) , the state's dominant phone company, had just under 12 million land lines in its 14-state territory as of Sept. 30, down about 9 percent from the previous year. But customers should think twice about cutting their lines, a spokeswoman said.

Land line service carries its own electricity, so in power outages, the home phone will work even when the lights don't, spokeswoman Joanna Hjelmeland said.

Local home phone service also is pretty cheap and fixed in price, she added, while it's possible to rack up large wireless bills if you're not careful and go over your allotment of calling minutes or text messages.

Comcast (NASDAQ:CMCSA) offers home phone service bundled with its cable TV and broadband Internet services and says it's not worried. The cable company's phone service grew by 2 million subscribers nationwide last year and now reaches 6.1 million homes, spokeswoman Mary Beth Schubert said.

Denver-based Qwest thinks new, pricier fiber-optic broadband services can save it from the cord-cutters. Qwest increased its broadband subscribers by 61,000 in the 12 months ending Sept. 30, with two-thirds of them buying its new fiber-optic service.

Broadband customers don't leave as easily as land-line customers, Qwest CEO Ed Mueller told a Citigroup (NYSE:C) analysts' conference last week. "The strategy is to make broadband our anchor," he said.

They might need one.

Lori Goldnick, 49, of Prior Lake, said her family of four, which includes two teen-agers, canceled home phone service in October.

"We're saving $40 a month, which is not a great deal of money, but every little bit helps," she said.

"When we told people we were getting rid of our land line, we got a lot of comments like, 'Oh, that's a good idea! I might do that too!' " Goldnick said.