David Regan keeps a picture of a Mercedes-Benz on his wall. Although the 23-year-old Arlington man already owns one of the luxury cars -- an old one -- he said the photo reminds him of all the things he wants but cannot afford. So to get them, he's working three jobs.

Adrienne Marra has four jobs. The Sterling mother of two juggles a complex schedule to provide money for decorating her house and buy extras for the family. To cope, Marra said she takes vitamins and even has learned to sleep standing up.

Orlando Valle said he grew up believing people had one job at a time. Now the Accokeek, Md., man with a master's degree has two jobs and soon will have a third. Because the cost of living in Washington is so high, he said, two jobs aren't enough.

In Washington, and across the country, an increasing number of people are taking on two, three and more jobs to meet high mortgage payments, acquire luxuries or gain experience to get better-paying jobs.

The ranks of multiple-job holders include college and graduate school alumni who either cannot find full-time work, need to pay debts or want extra money to maintain a flashy Washington lifestyle. Some are casualties of a weakening job market, economists said.

"We have a lawyer, we have an airline pilot who works for Eastern who's been laid off," said Peter McGhee, president of Diplomat Limousine Service, who added that a budget analyst recently asked about driving for him. "One fellow is an accountant for one of the universities here."

In 1980, about 4.9 percent of employed people had more than one job, according to the Bureau of Labor Statistics. That number rose to 5.4 percent in 1985 and 6.2 percent last year.

Not surprisingly, the cost of living has played a role. In 1985, 31.6 percent of multiple-job holders said they had extra jobs to meet regular household expenses, said Thomas Nardone, an economist at the bureau. That figure grew to 35.5 percent last year, Nardone said.

But the recent economic downturn also has played a role. The number of people nationwide working part time because they couldn't find full-time work or their full-time hours were reduced jumped from 4.8 million at the end of last year to 5.1 million during July, August and September, Nardone said.

"It's another indicator of the weakness in the economy," Nardone said. "When you have employment declining as we've seen it decline in the last three months . . . that's an indication that there's slack in the labor market."

Richard Groner, chief economist for the District's employment services, said many people who work multiple jobs in Washington do it because they became house-poor during the 1980s. "Housing in this area has been fairly high," Groner said. "Monthly mortgage payments on $200,000, $300,000 houses are not low."

Regan said he had intended to become a high school gym teacher or coach after graduation from college last year. He said the job market in Fairfax for teachers was tough, so he started working at the Carlyle Grand Cafe in Arlington, first as a host and now as a waiter.

He wanted to wait tables "mainly because it's automatic cash," Regan said. He recently acquired another job, recruiting promising high school athletes for a company that helps them obtain college scholarships.

"Even if I had one full-time job, I'd get a part-time job on top of it," Regan said. "Nowadays . . . I don't think I'd be satisfied with one job. If I had one job that paid me 300 grand a year, I'd have one job. Until then, I'll keep working."

In addition to the other jobs, Regan said he is an Amway distributor. He said his goal is to make $20,000 a month. Right now, he said, he's making about $1,000 a month. "Thank God I'm living at home," he said.

For Marra, the workday begins about 6:30 a.m. and ends about 10:30 at night. "I rarely sit down and watch TV or have a leisurely cup of coffee," she said.

On Tuesday, for example, she starts by tutoring seriously ill students at their homes for Fairfax County public schools. Between noon and 3 p.m. she teaches preschool classes in Leesburg. From about 7 to 9 p.m. she's at a Herndon drugstore, where she is the American Greeting card merchandiser. There she sets up displays and reorders merchandise such as wrapping paper, "and the latest now is gift bags," she said.

She also has her own company that matches teachers with students to provide after-school tutoring. "When I come home at 9, if I have phone calls regarding my tutoring service I'll start making them until about 10," she said.

Why so many jobs? "I think what happened was when I left teaching full time I felt the loss of income, naturally," Marra said. "We had been a two-income family for 10 years before I had my children. You become accustomed to many things in life."

Her income also provides "little extras for the children and we can be a little freer about going out to dinner," said Marra, who hopes to return to teaching when her children get older.

"I can't honestly say that I make that much money, that, well, we'll go on a lavish vacation next year, or we'll buy a very lavish car, a BMW or something like that," Marra said. "It amounts to keeping ahead of inflation. It just gives you that comfortable feeling and that I don't have to be too terribly concerned about the cost of everything rising."

Part-time work also has its downside. Benefits such as medical or other insurance, paid vacations and sick leave, and pensions rarely are provided. But 75 percent of people with multiple jobs also have a full-time job, Nardone said.

Valle didn't have a full-time job. When he received his master's degree in sports psychology from Ohio State University, he said, sending out more than 100 re'sume's didn't turn up one full-time coaching job. So he has two part-time jobs and is planning on starting a third in January.

His main job is an assistant coach for women's volleyball at Georgetown University. He supplements his income as an instructor at Courts Royal fitness club in Arlington. In January, he said, he'll start working for the Mid-Atlantic Volleyball Association teaching volleyball clinics to amateur enthusiasts.

Still, with three jobs Valle, 27, said he would not be able to live on his own. Georgetown's women's volleyball coach and her family provide a room for him in their house, he said.

With two part-time jobs, Valle said, he is paid about $900 a month with no benefits. He said if he gets injured at Georgetown, the university will handle his medical care. But if he gets hit by a car outside, he has problems.

Valle said he hopes that by taking on all these jobs, he'll not only have more money, but gain more recognition in sports.

Yet growing up, Valle said, he always thought one job would be enough. "Then I thought, hmmm, maybe it won't work out like that."