Putting the number in quotation marks helps you to find the exact match and the results will show only those sites that contain the number that you have entered within quotation marks.

Once upon a time, the Phone Directory and the Yellow Pages were considered sacrosanct when it came to looking for phone numbers. Alphabetically indexed, you just opened the Phone Directory to the appropriate page and you looked for the phone number of the person you wanted to contact.

Using the Yellow Pages, you just looked under the relevant heading and you got a comprehensive listing of all the companies in the state that dabbled in that business along with their phone numbers and sometimes even their address. Simple, yet brilliant!

Enter the age of the internet and it has rendered the Phone Directory and the Yellow Pages all but obsolete. With the internet you have access to phone numbers and addresses of people and businesses not just in your neighborhood or your state but right across the world.

Not only that, if you are armed with only a phone number and nothing else, the internet even enables you to ferret out the name behind the number. You can even pinpoint the exact location of the person.

This opens up a world of possibilities. No more do you have to wonder what happened to close friends you've lost touch with over time. No more suffering silently through pestiferous blank calls and obscene calls and no more speculating about the background of prospective employees.

Identifying and locating a person based on just the phone number is the simplest thing in the world. Much like you do any search on the internet, you just enter the phone number in any of the major search engines such as Google and in seconds the search results will provide you with the details you are looking for.

The process of identifying a person and locating them based on a phone number is called a reverse phone lookup.

One of the reasons why a reverse phone look up is possible over the internet is because people openly post their personal details including their phone number and address on to one or many social networking sites such as MySpace, Facebook and Orkut. When you enter the phone number in lieu of a search term, the search engine's spiders search through their database and if the requested number exists anywhere on the internet, it will show up in the search results.

On rare occasions it could happen that you may get more than one person that corresponds to the number. This is because another person may have had that number previously.

Why a reverse cellular phone lookup is not so easy

however, all this holds good only for getting information on landlines; these searches will not do you much good if you are trying to trace the person or an address behind a cell phone number.

You may get lucky if the person has posted their cell-phone on their blog or any of the social networking sites, but this is more an aberration than the norm.

One of the main reasons why reverse cell phone lookups are more difficult is because of stringent privacy laws, which make it illegal to publish cell phone numbers in any directory; whether offline or online, without the express authorization of the owner. Added to that is the very transient nature of cell phone number.

Hoever, for a fee that could range from $20 to $100, some records-brokers and actual "reverse cell phone lookup" companies will provide owner details on almost any cell phone number.