A personal profile, called CommunityNet, is established for each individual based on a novel algorithm incorporating contact, content, and time information simultaneously. It can be used for personal social capital management. Clusters of CommunityNets provide a view of informal networks for organization management. Our new algorithm is developed based on the combination of dynamic algorithms in the social network field and the semantic content classification methods in the natural language processing and machine learning literatures.

The Circle of Friends (1999) as implemented on Llantrisant Online (2001) allows users to add friends manually and recommends 'friends' from genealogical data, increasing their reputation when they add them.

This paper describes a technique for making personalized recommendations from any type of database to a user based on similarities between the interest profile of that user and those of other users.

Lenny Foner's PhD thesis on Yenta describes a privacy-aware matchmaking system based on the contents of a user's profile. The thesis caps much of the work, some published some not, of Pattie Maes's group at the MIT Media Lab during the mid-1990s. I would argue that this group's work pre-dates and was a superset of much of the social network tools now popular. Foner's thesis provides pointers to much of this

The system for recommending names on Facebook can be considered prior art under some circumstances. This is the same as described above with one difference: Facebook uses a k of 2 (everyone that is 2 degrees from the user, or one degree from the user's friends). In this patent application the value of k can vary to different maximum degrees of separation. Since k is a tweakable parameter, I would say that Facebook's present system IS prior art. (You can view this when selecting find friends and looking at the list under “Discover people you may already know”.