The couples are announced by number. One by one, they glide onto the floor, the men in crisply tailored black tuxedoes, the women in brightly colored ankle-length gowns that swish on cue.

They take their favorite positions on the dance floor; the music begins and they sweep across the room, sometimes locked tightly together in spins and dips, sometimes barely touching in parallel, synchronized strutting.

They're all there: The young, perfectly chiseled couples intent on winning the prize. The dowager women partnered with young male instructors with slicked back hair. The older couple moving with the familiarity of decades of social dancing. And 10-year-olds Robbie Hundley and Liana Turner, shuffling along with more precision than some twice their age.

The eclectic cast of would-be Freds and Gingers came from as far away as Canada and Great Britain this weekend to compete in the 26th annual Virginia State Ballroom Championship, which is considered the most prestigious dancing contest in the United States shy of the national championship.

"Ballroom dancing is a whole different world," said Marianne Nicole, 36, a dance teacher who traveled from Stamford, Conn. "Everything you've always wanted is here. If you enjoy watching the old-time movies and thought, 'Wow, I wish I could do that,' well, you can."

Easy for her to say.

True, most of the couples made it look effortless. But that belied the hundreds of hours of training and practice that preceded the four-day competition at the Marriott Crystal Gateway Hotel in Arlington that will climax tonight.

Like Olympic figure skaters, every move, every step, every twitch of the head was perfectly choreographed for the panel of scrutinizing judges. Whether it be traditional waltzes and fox trots or the Latin sambas and cha chas, form, poise and precision were everything.

Consider Dan Messenger and Ann Zabinski, reigning national champions in several professional-amateur categories.

When No. 110 was called, they didn't simply walk onto the floor, they glided. They concentrated on the heels, the toes, the heads, the arms. After a fluid waltz on the floor, they slipped out a side door to try to reposition his arm around her side slightly before the next round.

"The first trick even before you walk on the floor is proper grooming -- that you're immaculate head to toe," said Messenger, 29, a perfectly groomed dance studio owner from Milwaukee, dressed in a Victorian-style burgundy velvet tail coat. "They say half of it is a beauty contest."

The other half is the show. "Judges want to see showmanship," he said. "They want to see a performance."

So do the fans in the audience. As about half-a-dozen couples dance on the floor, the fans shout out the numbers of their favorites, game show-style.

While not nearly as popular as in Europe, ballroom dancing has a loyal following in the United States and Canada. More than 40,000 dance instructors teach in America and dancers travel the country, competing toe to toe in as many as 300 events a year, climaxing with the national championships in Miami Beach in September.

Couples change costumes as many as four times during one competition, with some women's gowns costing $2,000 or more. Outside the ballroom, merchants hawk specialized records, compact discs, videotapes, dresses, shoes, tuxedoes, jewelry. Some offer to videotape dancers for a price; a bank of more than half-a-dozen cameras were set up media-style in the back of the room.

The Virginia championship was started in 1965, a far more modest event in those days, and since then has grown into the warm-up for the national championships.

Founder Rickey Thornhill-Geiger attributes the increasing popularity of ballroom dancing to modern America's obsession with health. "This is very aerobic and it beats jogging in the heat on your own," she said.

Vincent Bulger, a New Jersey dance school owner and president of the National Dance Council of America, cites mass media influence dating back to John Travolta and "Saturday Night Fever" and continuing in more recent movies such as "Dirty Dancing."