In this paper we give a first summary of the ARSA project which tends to promote the using of social networks in public administrations, with experimentation in collaboration with the town of Antibes. The integration of social networks in administrations is tested in two directions: on the one hand we address the design and the installation of an internal social network that takes into account the hierarchical organization of the administration, but allows other types of relationships; on the other hand we setup a monitoring tool of the e-reputation of the town of Antibes on the external network Twitter. The two axes of this integration are discussed in detail in this paper.