1. A method for using social network information from a first online service provider network to modify a webpage provided by a second online service provider network, the method comprising: storing a webpage at a second online service provider network; receiving, at the second online service provider network, a request from a first user to view the webpage stored at the second online service provider network; sending, from the second online service provider network to a first online service provider network, a request for social network information related to a relationship between the first user and a second user, the request including a social network identifier for the first user and an identifier for the second user, the request being structured to use a defined interface to the first online service provider, the defined interface including one or more functions that each retrieve a type of information related to the relationship between the first user and the second user, and the first online service provider network being different from the second online service provider network; receiving, at the second online service provider network and from the first online service provider network, social network information related to the relationship between the first user and the second user; modifying the webpage stored at the second online service provider network based on the received social network information related to the relationship between the first user and the second user; and causing presentation, to the first user, of the modified webpage.