Over the last few years, the amount of information available on the internet has grown exponentially. This is true even more so because search engines like Google and Yahoo! make this vast amount of information searchable at the command of a single click. But these indexers of knowledge work only with publicly available information. The Information held privately is out of reach of these search engines and thus from you and me. One such type of information is mobile phone numbers. But even so, searching Google or Yahoo for a phone number should be the first method you should try, just because it is free and there is always a chance that it may turn up something. But you should brace yourself for a lot of junk pages in the search results.
Apart from the normal search, you should search for the number with quotation marks (for example: "555-555-4444"). Also, try entering the number with and without the dashes. It is highly likely that you will not get any relevant results just because cell phone numbers are in the private domain. At this point, your best option is to use a paid service. One such service is the Pacific Bell reverse telephone number lookup directory. One-time searches in this directory cost about $15, and the amount of information it provides in return is quite exhaustive.
This information would include the name of the person owning the phone number, whether they own other cell phones, and if so their numbers, the number of people living in their household, their address, previous addresses if any, and sometimes household income and employment information. If you need even more information, you can get that by looking up medical as well as police records for the name and address of that person.
It costs money to use a reverse telephone number lookup directory for getting information on a cell phone because the cell phone company's lease out their databases to the search directories. This is a business arrangement and the fee that you pay is their charge for the service they provide. The better directories allow you to do a preliminary search to see that they do have information about the phone number you are interested in, which is very helpful because this almost completely reduces the risk that your money will be wasted. Especially when combined with the 60 day, 100% money back guarantee these directories offer.