Land-line telephones, welcome to the party.

In recent years, as phone companies have beefed up their cell phones with a steady stream of enhancements, innovations to the old land-line phone have been slow to come.

But now, in a move largely designed to keep consumers from ditching land lines, phone companies are adding to home phones some of the features popular on mobile devices, like address books and text messaging. And equipment makers' latest home and office phones include a range of new features like in-home video baby monitoring, instant messaging, and access to e-mail and the Web.

The stakes are huge for the phone companies, especially those such as Embarq Corp., Qwest Communications International Inc. and Windstream Corp. that don't own their own wireless networks and are most susceptible to the increasing consumer shift away from traditional phones to cell phones. A recent survey by Harris Interactive Inc. found that 11 percent of U.S. adults use only their cell phones to make calls.

Land lines have traditionally offered better call quality than cell phones, especially indoors. But even that advantage is eroding as wireless providers address the issue.

Wireless provider Sprint Nextel Corp. recently began selling a Samsung product in some markets that acts as a mini cell tower inside users' homes, boosting a low signal to improve reception. It costs $50 and requires an additional $15 monthly subscription.

T-Mobile USA, a unit of Deutsche Telekom AG, now sells phones capable of operating on home Wi-Fi hotspots, another method of improving indoor coverage.

Given these developments, companies selling land-line phones are putting a higher priority on developing sleeker phones with more features.

"Any company concerned about defending a land-line customer base should be working on this," said telecom industry consultant Rory Altman.

Embarq, a spin-off of Sprint Nextel that has about 6.7 million subscribers in 18 states, is adding an address book feature to its home phones, allowing people to look up an entry and dial it by speaking a name into the handset.

Embarq is also testing a text-messaging function for home-phone users in some markets. When a text message is sent to a land-line number, the home phone rings, converts the message into audio, and plays it back. The land-line phone user can reply with an audio message or press a button to send a canned text response such as "Thank you" or "Where are you?"