When Esther Pauline Friedman Lederer and Pauline Esther Friedman Phillips sit down for a photograph, they slide into position with the complementary grace of two well-rehearsed dancers. "Slit on the left?" one identical twin asks the other, as she adjusts her long, beaded dress. "Slit on the left," answers the other. Left legs are crossed, slits slide open, smiles flash.

"Eppie" and "Popo," Ann Landers and Dear Abby, are ready.

Fifty years after graduating from Sioux City's Central High School, the two advice columnists returned this past weekend for their reunion. Although "The Friedman Twins," as nearly everyone here calls them, missed the evening of dinner theater, the Garden Buffet, the Champagne Brunch and the tour of the old school, now empty, they were there for the Saturday night banquet where they were the speakers.

When they made a stopover in Omaha to visit with one of their two older sisters (who dispense no advice, at least not publicly), they were met by photographers. When they arrived at the Sioux City Hilton, they were met by more. For the first two days of the reunion, the 170 members of the Class of '36 gathered here asked again and again, "When are the Twins getting in?"

When they finally did, even their classmates pulled out cameras.

"We've been anonymous and we've been famous," said Abby as they checked into the hotel, "and it's more fun famous."

A perfect Dear Abby retort; she was always known as the slightly more flip of the two. In fact, everything the two do is perfectly them. After 30 years of advising, the Twins remain the unchanging, ageless American queens of mottoes and snappy answers, ruling over a world where they counsel readers to "wake up and smell the coffee," a world filled with knowledgeable experts and inspirational poems and people they address feistily as "buster."

As children, these two petite twin daughters of Russian Jewish immigrants (born on the Fourth of July, 1918) dressed alike, crept into each other's bed, were never separated until the night of the day they were married in a joint ceremony. Now, more than 85 million people turn to the Friedman Twins each day to hear about alcoholism, whether money is an appropriate wedding gift, mental illness, spouse abuse, how to tell someone his fly is open, divorce and everything else from the trivial to the traumatic.

"Sissie, get your duds on and I'll help zip you up, dear," Abby calls across the hall before the Saturday night banquet.

"I can't imagine being a single," Abby says, as she fastens hook after hook running up the long cream silk sleeves of Ann's dress.

"Neither can I," says Ann.

"They used to call us freaks, 'Kate and Dupli-Kate,' " says Abby.

"But we were very much loved," says Ann. "We were the pets."

"Very much loved," says Abby.

If Ann's hair is honey blond and Abby's chestnut, if the faint lisp they share is a little more pronounced in Abby's voice, they remain echoes of each other nevertheless. Hand in hand wherever they walk, arms around each other when they sit, they lean together and giggle together like the two young girls who used to fool their violin teacher by sending Pauline in to class twice to cover for the less musically talented Esther.

One barely starts a thought before the other is completing it. With a sharp Iowa twang giving an edge to their opinions as hard and practical as the blade of a plow, they run along, racing each other to the end of the sentence. Whether talking about the letters they get every day (well over 1,000) or retirement, the race is unending.

Abby: "The load is enormous. It's gotten much heavier since we started . . . "

Ann: "We're adding papers . . . "

Abby: "I thought it would get easier as we went along . . . "

Ann: "We both thought it would get easier . . . " Abby: "Of course, we do speaking engagements, so we only have ourselves to blame, but we promise we're going to do that less . . . "

Ann: "I'm furious about that. I'm starting to do less . . . "

Abby: "So am I . . . "

But if, as they say, the letters are more numerous and the problems inside more serious, what with teen-age suicide and AIDS and the fear of nuclear war, do they ever succumb to weary depression and consider stopping?

Abby: "I don't feel depressed -- I feel exhilarated."

Ann: "I find it very rewarding."

Abby: "When you can help, it's not depressing . . . "

Ann: "When you can contribute . . . "

Abby: "I can't think of anything I'd rather do. Can you?"

Ann: "As long as my head and body hold out . . . "

Abby: " . . . and the good Lord lets me."

Raised by a mother who during the Depression always offered vagrants a warm place to sleep and a father who, in addition to owning a series of movie houses, was known for his delight in charitable work and homilies, Eppie and Popo were in training for their careers long before they even knew they would have careers.

Eppie, a housewife and mother of one daughter looking for a way to keep busy, took over the Chicago Sun-Times' Ann Landers column in 1955. Six months later, Popo, a California housewife and mother of two, created the name Abigail Van Buren and sold her column to the San Francisco Chronicle. Soon she was nationally syndicated and competing with Ann Landers. Eppie was not pleased. The rift lasted eight years.

By 1964, they were reconciled, but over the years there have been other moments of anger. In a 1981 interview in the Ladies' Home Journal, Abby said she had ghost-written many of the early Ann Landers columns, talked about the competition between the two and suggested her sister had a face lift to soften lines of sadness left by a painful divorce in 1975.

But now the two, having survived the ups and downs, are the Twins again.

"It's up now," says Abby, "and that's all that matters. It's been up for a very long time."

And when the two emerge from the elevator and wade into the crush of their classmates, they are together, their long, sparkling gowns and lofty, baroquely curled coiffures bright against the sea of pastel cotton dresses and soft gray hair.

"Oh, there they are, bless their hearts," someone in the crowd says with a smile.

While the TV lights arrived with their national fame, all the fuss started long before that.

"There was a splash wherever they went," says LaVerne Hoff, who taught the twins Spanish during her 18 years at Central High. All this time later, Hoff remembers Eppie and Popo as "very, very good, exceptional students," but a classmate offers, "Oh, they talked all the time. Teachers always had to hush them."

Being a member of the Central High Class of 1936, a member of the Twins' class, isn't without its drawbacks. Still, their close friends are endlessly loyal.

"They are the lovely girls I knew when I was young," says Leverette Jacobi, who lived near the Twins. "It seemed perfectly logical how it came out. They were reporters on the high school paper and then at Morningside College. What they did would be called investigative reporting -- they were looking for gossip and stuff like that. And they got it."

(Abby describes their gossip writing as "clever, witty, but never unkind.")

But for other class members, all of the Twin attention can grow tiresome.

"We came here to visit!" says Bill Rath of Santa Maria, Calif., after being asked all too many times what he remembered of "the Friedman girls." "They're just two graduates, and there's a lot of us. There are a lot of other people in our class who have done something."

The Central High Class of '36 has produced the head of the Export-Import Bank, a Montana state senator, an admiral, a general, an aide to Dwight Eisenhower, an executive assistant to three secretaries of state, Avon representatives, teachers, military people, antique collectors, engineers, mothers, fathers, mechanics and farmers.

Sioux City, like Iowa in general, has always been proud of its schools. One Central High graduate remembers that when a school superintendent died in the '30s, his hearse was followed by a procession of cars a mile long. "I think Central High School is the best high school in the whole world," said reunion chairman Charles Lindsay, a retired agent in the U.S. Treasury Department's organized-crime division.

"This is an unusual class. We're Depression babies, you know. We strived to give lots more to our children than we had.

"But what is success? Success is satisfaction in what you've done. The most successful person in our class was a girl who wrote to me: 'I have been a waitress for 55 years' -- that means she was working during high school -- 'I have served many famous people -- I will not name any of them. I am proud of my profession. I will not stop being a waitress until I have to.' That's success."

Like all classes, '36 has its more colorful members.

In the 50th anniversary book Bill Rath wrote: "Married 40 years, 4 sons, 2 granddaughters, have passion for 'Purple' and known as 'Purple People of Santa Maria.' "

"You've probably seen us on 'David Letterman,' 'Real People,' the National Enquirer," he says, when mention is made of his completely purple outfit and the button he wears that reads "Purple Partner."

Rath married into what his wife calls her "totally purple world." They have a purple house, purple car, purple clothing. She carries purple tissues, which requires the purchase of a six-package multicolor set -- she gives the other colors away and keeps the purple. He wears purple Hush Puppies. She is trying to figure out how to dye his red Swiss army knife.

"It started very soon after the war," says Jean Rath. She is wearing a purple blouse, purple slacks, lavender watch, purple shoes, lavender-tinted glasses, lavender-rinsed hair and the inevitable amethysts. "I was kind of into a yellow thing. Yellow was the first time I had a favorite color that wasn't my mother's favorite color. But yellow stationery was a real downer. I got onion skin, and when I put my blue pen to it, it turned green. That fact should have intrigued me, but instead I went to the store and asked if they had any pale blue paper. They had something called 'Wedgwood Blue,' but because the dyes were limited then, it was a pale lavender."

And thus was born a lifelong calling. Now Jean Rath sheds her trademark shade only once a year, when she gives up purple for Lent.

Earlier this year, Eppie and Popo ran brief notes in their columns about the upcoming reunion, encouraging fellow '36ers to write to Charles Lindsay for information. There followed the usual flood that follows the inclusion of any address in their columns.

"I've gotten letters from religious freaks, antiabortion, pro-abortion, you name it," says Lindsay. "A lady in Maine said, 'How much money did you have to pay Popo to get her to do this?' I said, 'These girls are classmates!' "

But the letters weren't only from strangers. Stan Sieler in California saw the notice and wrote to Lindsay.

"From the 25th on, we didn't have an address for him," Lindsay says. "I know what the 'lost sheep' parable means now. When we found him, I was elated."

For three days, this city has been filled with such people, Sioux Citians returning, seeking out vanished landmarks, pointing to the corner where a long-gone storekeeper in a long-gone store sold them their lunchtime milk, remembering the time an ice storm glazed the city and you could skate clear across town, reading in the quiet streets of Sioux City a map of their past and present.

"I drove around, saw all the old houses, and I have to tell you I felt depressed," said Sieler. "The city really hasn't grown a lot. I call it a dying city. But then I started meeting all the old friends, and even people I never knew, and pretty soon, I felt a hell of a lot better."

In the 1936 Central High yearbook, the Twins were, of course, wearing identical dresses. Popo was secretary of the Kamera Club, Eppie vice president of the International Relations Club. Next to Popo's picture it said, "Always with Eppie"; next to Eppie's, "Always with Po-Po."

"We always double-dated," says Ann. "We were very square. We didn't smoke. We didn't drink. We were quite prudish. It was 'Hands off the Friedman twins!' "

Abby: "Everyone was like that."

Ann: "That's true."

Abby: "And Momma and Daddy cared a lot about how we behaved."

Ann: "Being twins was sort of a protective device. We were always together."

Abby: "That's the saddest thing in our life -- that our parents didn't live to see us succeed like this. Into each life some rain must fall, and I think that's the rain."

Then it's time to go to the ballroom, where their classmates are waiting, cameras ready once again, sharing their stories about the Twins. "Well, I'll be interested to hear what they have to say," says Abby.

"Our consciences are clear," says Ann. "We were good girls."

"What is a good girl these days?" her sister laughs.

"You know," says Ann.

And doubtless, she does.