The number of homes destroyed or made permanently uninhabitable as a result of Hurricane Katrina is expected to far exceed that of any previous U.S. disaster, posing an enormous social and civic engineering challenge, government officials and housing experts said yesterday.

Facing an unprecedented need to find quick housing for what a Federal Emergency Management Agency official estimated could be 1 million displaced people, the federal government, corporations and private individuals are turning to previously untried and innovative strategies.

FEMA announced it had arranged for the first time to rent luxury cruise liners to house thousands of refugees for six months.

Mobile-home manufacturers, responding to pleas from FEMA, are adding shifts for workers to supply tens of thousands of travel trailers and mobile homes.

And in a remarkable outpouring, thousands of citizens around the country registered on newly sprouting housing-match Web sites to share their homes, in some cases offering to pay air fare and help find jobs.

Officials said they are even considering converting many of the nation's retired steel shipping containers into temporary mini-housing units.

"We're trying to get out beyond our normal modes of assistance," said Brad Gair, head of FEMA's housing command post in Baton Rouge, La.

FEMA has not made a formal estimate of the number of homes irreparably damaged by the hurricane. But with a large fraction of New Orleans's more than 200,000 domiciles expected to remain largely underwater for weeks or months to come, the number is almost certain to exceed previous records, according to the National Association of Home Builders.

Fewer than 30,000 housing units were destroyed by Hurricane Andrew in 1992, and a similar number were lost from the cumulative impact of hurricanes Charley, Frances, Ivan and Jeanne in 2004.

The most immediate goal, government officials said, is to get the homeless into situations that have at least a semblance of domestic normalcy.

Toward that goal, Carnival Cruise Lines of Miami announced it had agreed to charter three of its luxury ships -- Ecstasy, Sensation and Holiday -- to the Military Sealift Command on behalf of FEMA for six months. As of yesterday, the agency was in negotiations for additional ships.

"These are not the last three," said FEMA spokesman James McIntyre.

Ecstasy and Sensation, which can house as many as 2,600 passengers each, are to be docked in Galveston, Tex. Holiday, which usually takes people on four- and five-day cruises to Mexico and can hold as many as 1,800 passengers, will be docked in Mobile, Ala.

Carnival shipboard employees will continue to staff the ships, but luxury will not be part of the package. "Gambling and casinos, that's not part of the contract," McIntyre said. "We're just trying to get people into rooms."

Meanwhile, mobile-housing manufacturers moved quickly to step up production in response to requests from FEMA for 50,000 travel trailers, tens of thousands of mobile homes and "any other housing stock we can get our hands on," Gair said.

"We've been working all weekend, putting plans together and talking to various vendors and suppliers," said Mark Williams, a director of Stewart Park Homes of Thomasville, Ga.

The company, which normally produces about 1,000 35-foot-long mobile homes per year, has committed to crank out 500 for FEMA in the next few months, Williams said. The first of those, able to house four people and slated for delivery to Baton Rouge, will come off the production line Friday, he said.

FEMA "contacted us within 24 hours of the storm going through," he said.

Each 11-foot-wide unit includes a kitchen area, bedroom, bathroom with shower, and a living room with a sleeper couch. And there is a citizens movement afoot in Thomasville, Williams said, to stock the first 100 units bound for storm victims with additional items such as canned foods, extra sheets and coloring books and toys.

A similar community spirit blossomed over the weekend as people in states as far away as California and New Hampshire offered to share their homes with flood victims.

Reaching out through a half-dozen or more Web sites, homeowners across the country posted vacancy notices.

"We can provide a family of five or six a place to stay while rebuilding is completed," wrote one family in rural Deerfield, N.H., on a Web site (hurricanehousing.org) organized by the political advocacy group MoveOn. "We will pay for your airplane tickets, we can offer work and we will assist in getting kids into schools."

"We don't have a lot of money but are willing to share our home for as long as needed," wrote a Web poster in Nashville. "I have been down on luck before too, not as bad as you have it right now but had it hard and remember what it's like and want to lend a hand to someone else down on theirs."

Authorities had set up 563 shelters in 10 states as of yesterday, according to the Department of Homeland Security. The goal is to avoid setting up extremely temporary quarters such as tent cities or shipping container homes, unless absolutely necessary, said Gair of FEMA.

Gerald Mitchell II of Long Beach, Miss., gets a first glimpse of what used to be his home. With perhaps 1 million people displaced by Hurricane Katrina, government officials are turning to innovative strategies, such as renting cruise liners, for their housing.