Nearly three days after Hurricane Katrina ravaged New Orleans, Biloxi, Miss., and sections of the Gulf Coast, wireless and land line telephone service remains unavailable to many customers.

New Orleans remains underwater, and refugees are being evacuated from the Superdome to long-term refuge in the Houston Astrodome, As broken levees continue to pour water into the city, officials are preparing to transport 20,000 refugees out of the city and close it down indefinitely.

Both Cingular and Verizon Wireless report progress is being made to restore wireless service to the Pensacola, Fla., Mobile, Ala., and Baton Rouge, La., areas. Coverage is still extremely limited or unavailable in the New Orleans and Biloxi areas.

All Cingular and Verizon Wireless retail stores will offer free calling to the public as they are able to reopen, according to the companies. Customers are urged to use text messaging instead of calls to communicate, to free up the networks for emergency workers, and to allow messages to get through in a more timely manner. Text messages are more likely to get through in areas of high congestion or minimal signal.

T-Mobile HotSpot is offering free Wi-Fi service in Louisiana, Alabama, and Mississippi through Friday, and may continue offering the service for free beyond that time. The service is available at many Starbucks, Borders bookstores, and airports throughout the region.

Sprint Nextel customers as far away as Florida are being impacted by a long distance outage caused by one of the company’s major long distance switching centers being located in downtown New Orleans. The center is underwater and not functioning at this time. Long distance calls made to or from Sprint Nextel customers anywhere in the South or Southeast may not go through.

BellSouth reports that over 13,000 of its employees are in the hardest-hit areas and it plans to set up tent cities to provide them and their families with food, shelter, medical care and employee assistance such as cash loans. Some phones in the New Orleans metropolitan area are still working, as the central offices are running on generator power, but most land line phones in the area are out of service. BellSouth said today it has about 1.75 million customers in the affected areas.