Humans usually think of a location not as pair of coordinates but rather in a semantic way as place. In this paper, we are presenting a concept to integrate places in a framework for the development of user-centered community platforms. We follow a grassroots approach for collecting places and introduce an ontology- based place model along with concepts for mapping geographic coordinates to places. Furthermore, a place cloud is established as an intuitive user interface for localization, place visualization, and the retrieval of multimedia contents based on places. The prototypical implementation of our concepts proofs that places are well suited for personalization and the semantic annotation of multimedia contents in a social environment.