Abstract: Methods and systems for providing current email addresses or contact information to members within a social network are described. In one described method, an email program application requests an email address for a member within a social network. Using profile information associated with the member, the email address is provided to the email program application which sent the request. The email address is then entered into the send-to parameter field of an email message. In another described method, contact information associated with a first member of a social can be provided to a second member of the social network. The contact information is provided if the relationship between the first and second members is an authorized relationship. The contact information associated with the first member can be used to update the contact information for the first member in an electronic address book associated with the second member.

Abstract: Methods, systems, apparatuses, and computer program products for improving efficiency in transfer of content to mobile devices are provided. In a first aspect, hashing is used in a synchronization server to determine whether objects have changed, and therefore need to be updated on the mobile device and/or on the mobile device server. For example, databases are hashed on a record-by-record basis. Records determined to be changed are transmitted to the mobile device and/or updated on the synchronization server. In another embodiment, errors occurring during attempts to obtain unavailable web content are cached (i.e., “negative caching”). The cached errors are accessed during subsequent attempts to obtain the unavailable web content to avoid spending time on the subsequent attempts.