there is no definitive phonebook, of email address or phone numbers, however, there are websites that come close. Check this one out. - for reverse phone look-ups
One main reason why finding a person's address free online might be a challenge is because most people don't keep the same phone or cell number for long.
Another reason is that some people may use their second name when applying for a phone line and using last names only to find a phone number is a near impossible task. Some people don't even want their phone numbers to be listed on public records, which adds to the probability of never find the person's phone number free online.
Phone numbers vary by area
This means that when you want to find a person's phone number online, you need to narrow it down by a residential addres. If you do know where the person lives then you will be able to narrow your search. Some of the recommendations below are based on the fact that you have at least narrowed the "phone number search" by a residential area e.g. city or block if possible.
Use people in your phone book
Most often we keep a circle of friends - this means that about 80% of people you have in your phone book are acquainted in one way or the other. To find someone's phone number free by asking people who are in your phone book might just work. It is interesting how the little things usually prove to cause a major break through.
Use online telephone directories
We said earlier that if you know the person's physical address, then it is possible to find his or her phone number. This is especially true if you know the person's first and last name as well. Online telephone directories allow you to find people, business listings, phone numbers and listings. You can try Alexandria - one of the few phone directory sites that boast of a global coverage.
Find out where he or she works
Most companies have their employees profiles listed on the company's website or rather you may find that the person has reports posted by the company on some pages. Logging on to the company site and using the search engine found there might prove to be a winner. Type the name of the person as you know it and if nothing comes up use other alternatives like the person's position in the company and probably his or her nickname. The latter is uncommon in company documentation but when you really need to find someone's phone number free, anything is worth trying out.
Use Google operators
Google is the king of search - you can use it to find people's addresses or phone numbers free online. Using the Google operator "rphonebook will search residential listings, and the phone book operator will search all phone listing.
Other great sources to use for finding people's phone number free
You can visit other great websites like Phonewolf, which covers countries like Australia , New Zealand and the USA and other directories of free reverse phone number look ups. If you want to the mystery about the odd numbers you find on your phone PhoneSearch is for you. PhoneSearch central can provide accurate information so you can easily identify people who call you or who own the phone number that is showing up on your caller ID.
You may also find the following useful,
Using Google to find phone numbers free online