Find People
Infobel: International phone numbers and addresses.
PIPL: Addresses and phone numbers. Very up-to-date.
Private Eye: Searches way back and suggests connections to other people…remarkably accurate. There is a fee for some services.
Ultimate White Pages: Searches multiple sites, also has reverse look-up and a map link.
Virtual Gumshoe: Free public records directory.
Whitepages.com: Free reverse phone listing that provides name and address of the number's holder and a "Find Neighbors" feature that gives 30 other people at adjacent addresses; as well as "Get Map" and "Find Nearby Businesses".
ZabaSearch: United States phone numbers and addresses.