NEW YORK (CNNMoney.com) -- Personal assistants are often stuck with strange, thankless tasks, like fielding calls from a nagging mother-in-law, or approaching a handsome stranger on behalf of an employer looking for a date.
One woman, in need of a new bathing suit, had her personal assistant head to Bloomingdale's to get another shopper with a similar build to try on suits for her - in exchange for cash. (True story).
Of course, these assistants also handle the more quotidian matters in life, like booking flights, paying bills, returning calls, retrieving dry cleaning, and wrapping presents.
Personal staffers used to be the kind of luxury that was afforded only to members of the loftiest social strata. But these days, more and more busy, successful individuals are deciding that making dinner reservations themselves is simply more of a burden than they can bear.
Claudia Kahn, owner of The Help Company, a placement agency for domestic staff, including executive and personal assistants, nannies and chefs, says the demand for personal assistants has quadrupled in the last two years.
And, she says, it's not just celebrities calling her. These are "very busy people who have big lives," and who want someone to do their errands, manage second and third homes, or simply answer their phones.
With executive assistants tasked with professional duties, as well as nannies and housekeepers already on staff, personal assistants are the next logical hire for the overscheduled individual.
Mark Evans, a real-estate investor, is currently looking to add a fourth personal assistant to his staff. Evans, who travels often, said he needs an additional assistant to collect information on his various investments and generally ease his overwhelming workload.
"I'm a big picture, these guys are detail oriented," he said. But in addition to work-related research, Evans said his assistants, who earn about $1000 a week, help him with a wide range a tasks from making travel arrangements for his family to collecting the dry cleaning.
"They do everything except feed me," he joked.
As the professional assistant industry has blossomed, finding qualified help has become big business in and of itself.
"Twenty-four hours is simply not enough time in the day," said Dionne Mahaffey-Muhammad, owner of Celebrity Personal Assistants, Inc. and author of Beyond the Red Carpet: Keys to Becoming a Successful Personal Assistant.
"We have to offload our tasks to someone else - that's the only recourse an extremely busy person has."
Mahaffey-Muhammad said that when she started her firm in 1999 it was geared exclusively to celebrities and athletes. But now she works with more executives, philanthropists, socialites and other "behind the scenes" types.
"I believe everybody can use a part-time personal assistant, although not everyone can afford one," said Jill Glist, founder of New York-based Lambent Services. Glist started her business in 2006 after she hired her own personal assistant and realized just how valuable an extra set of hands can be.
Now Glist, a Yale graduate herself, staffs only graduates of "Ivy League or Ivy League-comparable" schools, and says her pool of personal assistants are "presentable, smart and mostly young."
They cost between $35 to $50 an hour, but Glist encourages her clients to engage help on a long term basis. Of course, full-time help does not come cheap. Assistants generally make between $60,000 and $80,000 a year, but can earn as much as $120,000 to $150,000 schlepping for an A-list star.
Good personal assistants have lots of professional contacts to help them get a wide variety of tasks completed. "They know the personal shopper at Barney's or where to get a cashmere blanket mended," said Kahn.
Soon, she predicts, personal assistants will be as popular as nannies and mannies.
"It is a 24-7 job," Glist said. "If a faucet erupts they really are the person that has to call the plumber." 
