Doing a reverse lookup can bring up a name and even an address, so that you know who it is that is calling you. The two primary types that you will find are traditional phone directories and reverse phone directories.
That is why the only reliable and guaranteed reverse cell phone look up sites are those that require you to sign up as a member for a very small fee. And you don't even need to know the person's name or in which city or county they live. If you were to get a call from an unknown number in the past, you could not do much other than call your phone company to see if they can give you more information.
However the fee is a one off payment and you can run as many searches as you like once you have access. All you need to do is to enter the number you are searching for, the area code and 7 digit number and the service will run through its database and return your matched results. If you haven't yet ventured online to find a phone number, find one of the online residential phone number search engines and try it out.
As always your searches are guaranteed legal and confidential. Some harassment may come in your mail box and some on the phone, so it is nice to be prepared.