Bachelor Thesis from the year 2008 in the subject Computer Science - Internet, New Technologies, grade: 1,3, University of Bremen, course: Mediainformatics, language: English, abstract: This Bachelor-Thesis deals with the synchronisation of social network services. This type of internet application enjoys great popularity which results in new challenges for identity and relation management. On one side the user has to manage different identities and on the other side a friendslist per social network service. From this effort arose to make data portable and reusable for example in order to avoid re-declaring friends to every site. To accomplish this goal numerous projects and technologies have been developed, which already provide partial solutions for this problem. The basic conceptual question however how to deal with the problem generally is still open. Moreover some of the techniques are only suitable for special use cases or else not ready für a professional use. In this thesis some of the existing standards shall be used to tie them together to one total system. This system consists out of a central identity provider, which functions as a central storage for the users contact data. By utilising interfaces this contact data can be exchanged with the social network service and by that improves the relation management for the users.