Sites of social networks are relational spaces where ‘we act’ and ‘we produce’ (texts/speeches, photos/memoirs, videos/actions, audios/preferences). The ‘we act’ bit of the performing side of everyday life finds in the social networks of the Web a ground for experimentation and creativity. The author’s paper starts from the ‘participatory culture’ framework by Henry Jenkins, showing the first results of an on-going empirical research developed by the author within the PRIN research project "CoOPERARE-Content Organization, Propagation, Evaluation and Reuse through Active Repositories". The author focuses on the mainly visual analysis of the user generated contents on Flickr, with particular emphasis on the domain of Cultural Heritage. The research methodology is based on an interdisciplinary approach, conducted in close collaboration with IT experts, testing new research methods, both in data and information sampling inside Web 2.0, and in semi-automatic analysis of large numbers of data. The motivation driving this research is to find out recurring or unusual "behaviours" in producing photographs in Flickr, by applying a visual analysis to a large number of photographic data. Three main theoretical frames support the author’s interpretation: the "tactics" by Michel De Certeau, the "habitus" by Pierre Bourdieu, and the "performance team" by Erving Goffman.