Their names are synonymous with luxury: Black Tie, Top Hat, Executive, VIP. Just don't call them potties.

Boasting amenities that range from tuxedoed attendants to brass fixtures and oak paneling, upscale portable restrooms are showing up everywhere from weddings to PGA tournaments to President Bush's ranch.

The luxury commodes make up a growing segment of the portable sanitation industry, catering mostly to women who refuse to use the typical blue or green boxes that pass for bathrooms at most outdoor events.

"Men, they'll go behind a tree. They don't care. We cater to women," said Larry Kettwig, who works in operations for Black Tie Services, an upscale mobile restroom business based in Lockport, a Chicago suburb.

Black Tie is among a handful of companies across the country that specialize in the restrooms, which from the outside look like plain white trailers. The surprise is inside, where vanity mirrors, flushable toilets, full sinks, piped-in music, air conditioning and potpourri make the restrooms almost indistinguishable from those in a home or nice hotel.

"It's definitely a growing trend. Like anything else, there's always people who want to drive Cadillacs or Rolls-Royces," said Barry Gump, president and CEO of Andy Gump Temporary Site Services, a Valencia, Calif., company that has serviced million-dollar weddings and Hollywood soirees.

Right now the trailer suites -- which range from a couple of bathrooms to more than a dozen and average around $3,000 to rent -- are mostly seen at corporate hospitality tents or dressy outdoor events like weddings.

But Dave Bandauski, president of Black Tie Services, said the demand has grown as more event planners realize women leave parties when the restrooms aren't up to par.

Bandauski started Black Tie in 1998 with three trailers. Now the company has more than 100 that are constantly on the move across the country. The company's trailers recently have appeared at parties at President Bush's ranch, gubernatorial inaugurations in Illinois and Florida and the Bobsled World Championships in Lake Placid, N.Y.

"The number of units we have is nothing compared to the demand and the future demand," said Bandauski, who already has the summer booked with events.

Courtney Leddy, who works in sports public relations in New York, was, well, relieved to see an upscale trailer when she attended a corporate event at the U.S. Open golf tournament in Bethpage State Park last year.

"I asked where the restrooms were and they pointed outside, and I was, like, great, a disgusting porta-potty," Leddy said.

Instead she found fresh flowers on a marble countertop, carpeted floors, a private stall and real towels. "I was, like, this is the nicest porta-potty I've ever been in in my life!"

The units aren't cheap, which has limited the number of companies able to enter the business. Trailer suites range from about $55,000 to $250,000 to purchase.

Even so, Kohler, the Wisconsin-based manufacturer of kitchen and bath fixtures, believes the demand will continue to grow. The company began its own mobile division about two years ago. Its trailers cost between $70,000 and $250,000 and feature Kohler fixtures.

"This seems to be the largest growth sector of the industry," said Jeremy Knopow, general manager of Kohler Mobile Plumbing Systems. Knopow may be right, judging from the raves of those who used the 27 plush private bathrooms in a promotional trailer Charmin bath tissue put on the road last year and called "Potty Palooza."

Renee Catacalos used the trailer at the NFL Experience during the Super Bowl in San Diego and deemed the attendants, wallpaper and lighting sconces "unbelievable."

She's all for trailers phasing out the more typical toilets.

"If you really have to go, you go to them," she said of standard potties. "But you kind of make this mental calculation: 'When am I going to be in a place with a bathroom?' "

Dave Bandauski, president of Black Tie Services, in one of his company's deluxe toilet trailers.David Bandauski in the Black Tie Services showroom. Black Tie, one of several companies that offer luxury commodes, has provided facilities for gubernatorial inaugurations in Illinois and Florida.