Whocalled.us is a website that allows users from all over the country to log phone numbers of people who have called them. Once the phone numbers have been logged, there is another page where users can look up the numbers.
By looking up the number, the hope of the user is to find out who a number belongs to, especially if the number is one that is unknown to him. People can log any phone number they want, including their own, if they want to be listed on the website's directory. Once a number is looked up, the service lists the owner of the number, if known, as well as the zip code associated with the number.