Pervasive computing middleware, to support thespatially and socially situated activities of users, has to eectivelysupport both self-organizing spatial activities and socialmodels of interactions. In this paper, we present the solutionthat we are going to integrate in the SAPERE middleware totackle this problem. The basic idea is to exploit the graph of asocial network (e.g., Facebook), in conjunction with relationsderiving from spatial proximity, to drive and rule the actualtopology of interactions among devices, users, and services. Aswe will discuss trough this paper, such an approach: facilitatesthe autonomous and adaptive activities of pervasive serviceswhile accounting for both social and spatial issues; supportseective service discovery and orchestration; enables tacklingcritical privacy issues.