Getting someone's telephone number can be tough, since nearly one in eight households have dropped their landlines and are totally wireless. You can't find numbers for cell phones in the phone book, or by calling 411.

But now there's a new list that makes it easier to track down cell phone users. And the mobile phone directory is the first of its kind. Consumer advocates caution, the directory may NOT always be the right call.

Arlen Ruiz discovered Intelius when she couldn't get information anywhere else. "It's not very easy," she said.

Intelius recently put out its own directory of mobile numbers. Ed Peterson of Intelius talked about it. "The market demand for this cell directory has been enormous. Our transactions on the product literally have doubled in the last month and a half."

Using it is easly. Go to the cell directory on the company's site, type in the name of the person and the system tells you what's available, from address, to home phone to cell phone. You can also do a reverse search to see who a number belongs to. Viewing the information costs you about $15.

Ed Peterson told us it's not for everyone. "The primary use for that service is a parent or someone trying to get information on who may be calling them or one of their loved ones."

Arlen Ruiz says most of the people she knows only use cell phones. "If I needed to find a friend's number that I haven't seen since high school, then I think it would be a great idea."

But consumer advocates say cell users have an expectation of privacy, since incoming calls use up costly minutes.

Beth Givens is with the Privacy Rights Clearinghouse. "Many people, if not most, pay for the receipt of calls to their cell phones and they want to have some control about who calls them."

Intelius says if you don't want to be included…you can opt out.

Privacy is not the only issue. The wireless industry is concerned about accuracy, because the directory is compiled from marketing lists and public records...Not information from the carriers themselves.

That concerns Joe Farren, who is with The Wireless Association. "Only the wireless carrier has accurate, up-to-date information. They're the ones that know who their current subscribers are."

We wanted to see how well the directory works… we asked Arlen to try it out. She looked up the cell phone numbers of four people, including herself.

She didn't fare so well. "It didn't work at all."

It wasn't a matter of accuracy for Arlen, but availability. The directory didn't have any of the cell phone numbers she was looking for.

Intelius says the directory contains nearly 40-percent of U.S. wireless numbers so far, and is constantly expanding.
"The product really is in its first generation and you'll see improvements in the coming months," Ed Peterson explained.

Arlen says she'll hold off using it for now. "I'll wait a couple of years. Hopefully by then, they'll have more numbers.")

The cell phone industry has been in talks for years about creating their own wireless directory. No plans are set yet, but if one is created, they say numbers will only be included if the customers give permission first.

Intelius says if you get wrong information during your search, refunds are given on a case-to-case basis.