The book at hand re'ects on the increasing convergence of Social Media and Semantic Web technologies. It was the editors' intention to collect - to-date and high quality contributions that illustrate various approaches to this young and emerging technology area. To guarantee this we invited be- of authors from the international conferences I-SEMANTICS and I-KNOW from the years 2007 & 2008 that took place in Graz / Austria to prepare - tended contributions...