(FORTUNE Magazine) – "Directory assistance. What city and state, please?"

"Operator, help! I'm stuck in traffic, and I'm late for a meeting with an extremely important client. This woman's name is strictly A-list--I mean, she gets more Google hits than Donald Trump--and I'll be in serious trouble if I don't reach her. Only I can't find her mobile number ..."

"No problem, sir. I can look up your client's cell-phone number in my system and connect you right away. Now, did you say her name is Strictly A. List?"

That exchange is, of course, preposterous--and not just because our modern-day Ernestine is polite and reassuring and didn't rush her frenzied caller off the phone. We know the scenario is pure fantasy because there is no such thing as directory assistance for cellphone numbers.

Information, please! How can that be? After all, more than 158 million Americans now have cellphones, and analysts believe some 5% of them have disconnected their home phone lines in favor of an all-wireless existence. (If you don't have a home phone number, you probably aren't listed anywhere.) Yet because of privacy concerns--no one wants to get telemarketing calls or spam messages on mobile devices--and the fractured nature of the U.S. wireless business, the telecom industry never launched 411 for cellphone numbers. So desperate consumers resort to a low-tech scavenger hunt: We dig through stacks of business cards, hoping to find someone's cellular number scribbled on the back. Or we call our target's voicemail, hoping to find the information on the outgoing message.

Now a group of wireless companies--including Cingular, Nextel, Sprint, T-Mobile, and Alltel--hopes to bring cell service into the mid-20th century by compiling a national database that 411 operators can tap into to find wireless numbers. The consortium, inventively named Wireless Directory Assistance LLC, hopes some members can launch the service later this year. But don't start dialing in hope of scoring Lindsay Lohan's cell number. First, that's just creepy. But more to the point, the companies say they are going to let cellular customers decide whether they want to be listed in the database. (When you order plain, old telephone service for your home or business, your number is automatically included in directory assistance unless you pay--up to $60 a year in some states--for the privilege of being unlisted. As a result, roughly 80% of "land line" phone numbers are listed in directory assistance and printed phone books.)

Letting customers choose to be listed in the database sounds like a rare consumer-friendly move by the wireless industry, but it also means the new service won't be very comprehensive. The telcos will need to contact every customer, explain how the new 411 system works, and hope for the best. A similar "opt in" initiative in Australia has drawn only 10% of wireless numbers. Guess you're not going to nab Nicole Kidman's cell number either.

But an even more prominent holdout threatens to scuttle the entire project. Verizon Wireless, the largest cellular provider in the U.S., with 40 million subscribers, says it won't participate in the database. "We've talked to our customers, and they tell us they want their wireless numbers kept private," says a Verizon rep. The other carriers, in turn, won't let Verizon customers independently add their wireless numbers to the database. "The only way they could do it is to come to one of the consortium members," says Jeff Schlueter, executive director of product management for Cingular, the country's No. 2 wireless provider. He chuckles, "They can always [switch] their numbers over to Cingular." That's optimistic, but for now a quarter of wireless numbers won't immediately be available to the database.

It wasn't supposed to be this way. Cellphones were going to make people easier to reach, not harder. Nearly a century ago the old American Telephone & Telegraph Co. understood the importance of providing customers with a simple, elegant way of finding other phone users--otherwise, people might not take full advantage of their newfangled talking machines. A group of AT&T operators called the Department of Information, dedicated to looking up phone numbers, had formed in New York by 1906, and by the 1920s it had spread to major cities throughout the Bell System. Giving the public easy access to all that information, says AT&T corporate historian Sheldon Hochheiser, "increased the value of the phone service."

And so began America's rich heritage of innovation in the information-services arts. As the popularity of the number looker-uppers grew, AT&T renamed the service "directory assistance" to prevent kids from calling "information" for help with homework. Computers eventually replaced the cumbersome books operators used to find numbers. And a few years ago most phone companies started offering national 411: An operator sitting in Nebraska can now locate the number for a dry cleaner on New York City's Upper West Side.

And yet the great telephonic minds that whittled the average length of a 411 call down to mere seconds haven't figured out a way to add the entire universe of wireless numbers to the mix. Wireless directory assistance does exist--in the land of lutefisk and socialized medicine: Sweden, Norway, Denmark, and Finland all have national wireless directories, and consumers in those countries apparently list their cellular numbers without reservation.

But America may still regain its information leadership. Backers of the new wireless directory say consumers need not worry about privacy: It already is illegal to make telemarketing calls to wireless phones, and the new Do Not Call registry adds another layer of protection for consumers who don't want to be hassled on the move.

And let's not forget that wireless directory assistance is another way of milking more money from consumers, something at which American phone companies excel. Directory-assistance services have gone from cost centers to potential cash cows, says Kathleen Pierz, who runs the Pierz Group, a telecom consulting firm. She figures that the price of a local 411 call has gone up throughout Verizon territory an average 60% since 2001. And directory services give wireless companies a double dip, revenue-wise: They collect a buck or more for every directory call, plus they get you to use up some of your wireless minutes. Pierz estimates that the cellular carriers could make an extra $1.6 billion a year from wireless 411.

In fact, Pierz and others think directory assistance could be much more than just a repository for phone numbers. She argues that the phone companies, with some new software and employee training, could begin offering new services, such as a system that allows an operator to forward, for a fee, a text message to the unlisted customer you're trying to reach. And why stop at wireless numbers? Directory assistance could list e-mail addresses, work numbers, website addresses--or any other info-nugget a customer might desire.

That may seem like a lot of data--or at least a level of detail found only in your average PDA entry--but directory partisans insist it can be done. When that happens, assuming it does happen, "information" will finally enter the Information Age.

FEEDBACK smehta@fortunemail.com