Nisonja McGary has two in-office personal assistants, but when she needed to hunt down a pair of Gucci Veruska pumps, she didn’t summon them. Instead, she dialed 611 on her phone, tapping into a 24-7 virtual concierge service offered by Voce, her cell phone carrier. “My assistants are good at running around and getting things done, but they wouldn’t have known how to find this shoe,” she says. A Los Angeles-based stylist for entertainment executives, McGary needed a pair in nude, a color that wasn’t on sale in the U.S. Using research skills and a network of connections that McGary says her office assistants lack, Voce’s personal assistant called stores and warehouses around the world and delivered the goods.

McGary is one of an increasing number of people turning to alternative personal-assistant services—many of which are virtual or remote—that can either supplement existing office assistants or even replace them. No longer confined to hotel lobbies, concierge services are also popping up in various forms all over the world—with now more than 650 services globally, according to Katharine Giovanni, chair of the International Concierge & Errand Association.

The association has grown 45 percent in the past year and a half and includes individual concierge services. Some services are remote-access only, such as Get Friday, a company whose assistants will manage your life from their desks in Bangalore, India. Others are linked to rewards programs and credit cards, including the exclusive American Express Centurion Card. McGary’s virtual concierge comes in the form of a $200-a-month cell phone service.

So what do these virtual assistants do? While prices and levels of service vary, an outsourced concierge can handle almost any detail that doesn’t require face-to-face interaction. Restaurant reservations and theater tickets are common requests, but many assistants help out with more-involved tasks, such as researching the background of potential clients and identifying sales leads. Obviously, a remote assistant can’t pick up your dry cleaning; they can, however, arrange to have it delivered to you.

Customers of Get Friday are assigned a transcontinental point person who’ll perform daily wake-up calls and read bedtime stories to children over the phone for $15 an hour. Stuart Jeffries, C.E.O. of Killer Grinds, an I.T. budget consultancy based in Laguna Beach, California, uses Suresh, his Get Friday assistant, for everything from ordering deodorant and back issues of Maxim to checking his cell phone messages every day at 10 a.m. “Most messages I get are two minutes long, and my brother talks too much, so if I have 15 messages, that’s a half hour of my time,” he says. “Suresh can truncate my messages and type them in an email.” Jeffries has an in-person assistant who helps out once a week, but Get Friday is much cheaper than having a full-time staffer. Plus, says Jeffries, “It’s fun and interesting.”

Some requests are truly outrageous, such as the convoluted task that Tom Larance, who runs Corporate Concierge Services in Chicago, took on. At the request of a 40-something female executive running a temp agency, Larance located a hypnotist to help her lose weight and then found her a psychic who could confirm that the hypnotist would work. The case is an example of the beauty of a virtual concierge: No one knows what you’re doing, particularly not the personal assistant seated outside your office who might gossip at the water cooler. “Your concierge is never going to give you up,” says Larance. Indeed, many concierges are required to sign confidentiality agreements, and discretion is generally tacit across the industry.

Another benefit of going virtual is the vast network of resources that a remote assistant can access. The I.C.E.A.’s Giovanni says a member once received a request from a musician who was performing in New York but left his jacket in Florida. She harnessed her network and found someone who could fetch his jacket, get on a plane, and hand-deliver it. And while the idea of one personal assistant at your beck and call seems more individualized, many virtual concierges are available around-the-clock—even when your real-life assistant might be sleeping. “I can’t call my assistant at 1 a.m., and if I did, she’d probably kill me,” jokes Voce customer Aric Ackerman, C.E.O. of the Hollywood postproduction company L.A. Studios.

Granted, some tasks don’t always translate remotely. Jeffries loves the convenience of not having to listen to his brother’s long-winded voicemails, but since Suresh didn’t understand American accents well, Jeffries had to give him extra training. And there are some tasks virtual concierges just won’t do. Giovanni says concierges will do anything in the yellow pages but draw the line at illegal, immoral, or unethical activities. “We won’t get customers ladies of the evening,” she says.

McGary’s needs are far less racy. Gucci shoes notwithstanding, she generally calls Voce a half-dozen times a day to locate particular items, like a decanter and wine glasses by Nambé, Rachel Ashwell Shabby Chic bedsheets, or discontinued accessories for her Apple computer. Right now she has Voce on the case to find her an elusive pair of yellow Moschino pumps that have yet to be spotted in America. But McGary will never give up her in-office assistants. Because after all, once her virtual concierge finds what she needs, someone has to go pick it up.