(MONEY Magazine) – Essential as it is to a successful retirement, financial security is only half the story. Remember that if you quit work at age 65 you should expect to live two decades -- half a career -- in retirement. Planning how to spend those years is every bit as important as planning how to pay for them. One thing is certain: you can't be on vacation the whole time. ''I often see people whose only retirement plans were to travel and play golf,'' observes Paul Westbrook, a retirement planner in Watchung, N.J. ''After about six months it becomes clear to them that they have to find something else to do with their lives.'' The best time to start looking is before you leave work. ''If you can't say what you are retiring to,'' says Philip Dreyer, a psychologist at the Claremont Graduate School in Claremont, Calif., ''you probably aren't ready to retire.'' To jog your imagination, jot down favorite activities that were squeezed out of your life by family or career. Not every old passion is possible or appropriate to take up again, but even rejected ideas may lead to something. For instance, says Richard Cripe of Denver, a psychologist and corporate consultant, ''You may not be able to play soccer as you did in college, but you can coach it.'' Once you have settled on activities for your retirement, look for opportunities to give them a trial run. A handful of companies, such as Polaroid, allow retiring employees to leave work for several months and then come back on staff for a few months or even years if they feel they are not ready. If a retirement rehearsal is out of the question, you can still smooth the transition by putting more time into retirement activities and less into work as your career nears the finish line. In the stories below, meet three couples and a widow who -- each in a different way -- turned retirement into the opportunity of a lifetime.

A double-scoop success for a retired restaurateur Energetic, Austrian-born Walter Lappert has made and lost two or three fortunes in a colorful entrepreneurial career that included stints as California restaurateur, Ecuadorian distiller and purveyor of liquor to the | Venezuelan military. Six years ago, Lappert, then 61, turned his three Sausalito restaurants over to his son and retired to the Hawaiian island of Kauai. ''Walter is not the type to take it easy very long,'' says his wife Mary, now 31, who met her husband through her brother, who managed the restaurants, and married Lappert in 1977. ''After a couple of swims, it was 'What's next?' ''

The answer came on a stroll near their one-bedroom apartment in the town of Poipu, when they bought a pair of ice cream cones. ''They tasted like old socks,'' recalls Walter. He decided he could do better. Within months, the couple had put up $150,000, half their savings, to build a modest ice cream factory and shop in nearby Hanapepe. If the Lapperts' operation was spartan, their product, Lappert's Aloha Ice Cream, was anything but. They used vanilla beans from Madagascar, chocolate from Belgium and native Hawaiian guava and macadamia nuts. The first 4,500- gallon batch sold out within two weeks, and it was clear to the Lapperts that they had a thriving business on their hands. Today the Lapperts sell their rotating menu of 125 flavors -- from Guava Cheesecake to Poha Berry -- through about 75 stores and dozens of restaurants in Hawaii and California. The operation brings in annual revenues of more than $10 million, on which the couple will net about $400,000 this year. Mary oversees production at the couple's expanded plant, where 15 employees turn out 18,000 gallons of ice cream each month. Walter handles sales and public relations. They work 12-hour days, six days a week, but the schedule seems to agree with them. Pointing out that the lease on the land underlying their original shop expires in 35 years, Walter, now 67, says: ''I plan to renew it personally.''

A Minneapolis octogenarian is reborn a star A lot of actresses think they are washed up if they haven't had their big break by age 30. Nina Draxten of Minneapolis didn't get hers until after she turned 81 three years ago. Since then the retired junior-college English teacher has appeared in seven industrial training films, 15 print ads and 12 television commercials, including a nationally aired Burger King spot in which she played Herb the Nerd's schoolteacher. ''After 40 years of memorizing poetry for my English classes, learning lines came naturally,'' says Draxten. She landed her choicest role last October, when director Sam Shepard cast her as actress Jessica Lange's grandmother in the feature film Far North, due for release this fall. Until recently, Draxten hadn't performed since her undergraduate days at the University of Minnesota, 65 years earlier. But in 1984 her brother Chester died, and the never-married Draxten turned to acting as a way to combat loneliness. ''She had poise in front of the camera,'' recalls agent Dee Ulsaker of Draxten's first screen test. ''There was a natural talent there.'' Draxten has refused to let stardom go to her head. She deposits all of her annual show-business earnings -- about $5,000 -- in a money-market account. (Social Security payments of $8,400 a year and pension benefits of $4,800 cover her living expenses.) During the long Minneapolis winter, she shovels her own walks, and between auditions she writes: the Norwegian American Historical Society has published her biographies of two prominent 19th-century Minnesotans, Karl Janson and M. Falk Gjertsen. Sound like a Frank Capra script? Says Draxten: ''It's a wonderful life.''

A personnel manager leaves Big Blue for green acres Retirement has held few surprises and even fewer moments of idleness for Jake Bius since he left IBM's Atlanta office at age 55 last summer. But that is exactly the way he wanted it: all of his important first steps in retirement -- moving to a 44-acre pecan farm near the southern Georgia hamlet of Barney, teaching marketing six hours a week at nearby Valdosta State College and working as a consultant -- were carefully mapped out before he quit Big Blue. Marvels his wife Betty, 54: ''Jake is a long-range planner in almost everything.'' Betty, a retired nurse, is content to leave all that to her husband. For much of his 30 years as a planning, marketing and personnel manager for IBM, Bius had hoped to retire at age 55. He began planning his post-retirement career in earnest seven years before he left the company. To get ready for teaching, he earned his M.B.A. weekends and evenings at Georgia State University. Next he requested a transfer to an IBM education division, where he taught sales and presentation skills to high-level managers and picked up valuable classroom experience. The preparation worked: he became an assistant professor at Valdosta State, even though he lacks a doctorate. Bius also runs two consulting businesses. One is a nonprofit venture aimed at charitable institutions; the other caters to corporate clients such as IBM and Citizens & Southern Bank in Atlanta. The business, together with his teacher's salary, pension and investment earnings, brought his income last year to more than $100,000. Characteristically, Bius had a firm idea of the farm he wanted: it had to have a pecan orchard, fish ponds, hay fields and a barn. The $160,000 spread that he and his wife acquired and moved to last winter met all his requirements. So far, chores have not interfered with Jake's other work. ''I haven't had one moment's disappointment in the farm,'' he says. And Betty? ''Well, I have always been flexible,'' she says. ''I'm learning to love the farm more every day.''

A librarian and an economist hit the books in retirement ''Life should be a continual process of learning,'' declares Alice Luney, 66, of Durham, N.C. Since 1984 the retired head of library acquisitions at Catholic University in Washington, D.C. and her husband Percy, 65, a former economist for the Department of Agriculture, have been following that axiom. In their youth both Luneys earned master's degrees -- Alice in library science at Catholic and Percy in agricultural economics at the University of Kentucky. But now at the Duke Institute for Learning in Retirement, a 10-year- old noncredit education program sponsored by Duke University, they satisfy a wider-ranging intellectual curiosity. For $95 a semester the Luneys can take as many courses as they please: this spring they attended classes conducted by other DILR members and Duke faculty on existentialism, black history, St. Augustine's City of God, the history of the Bible and the geography of Canada. The Luneys appreciate the company of fellow students as much as the classes themselves. ''The people there are widely read and have done many things,'' says Percy. ''You can talk about anything.'' Alice has also taught courses at the institute on short stories and North Carolina Indians. Percy, meanwhile, earned his real estate broker's license in 1986 at Durham Technical Community College and in 1982 took H&R Block's training course for tax preparers. While he has sold a few homes, he and Alice don't need the money -- the income they receive from Social Security, pensions and investment earnings suffices. So he mostly uses his new skills to help friends who ask for advice on real estate and to counsel senior citizens and low-income people on their taxes for free. Like any students, the Luneys enjoy study breaks, which include gardening in the yard surrounding their eight-room brick ranch house, meetings of the alumni chapter of Percy's fraternity, Alpha Phi Alpha, and frequent babysitting for their two granddaughters, ages 5 and 7. (Their son Percy Jr. is a law professor at North Carolina Central University in Durham.) Last year they gave themselves a fall break to sightsee in Nova Scotia; this spring they plan to ride burros down the Grand Canyon. But in the meantime, if you will excuse them, they have homework to do.