If you have the phone number of a person or business, you can find the address as long as it's not listed as private. This type of service is called a reverse phone number search. It's free, and all you need is Internet access.
Browse to the White Pages website (see References for the link).
Type the area code and phone number you wish to track into the box under "Reverse Phone."
Click the "Find" button. The names and addresses associated with the phone number will be shown under "Results."