This book constitutes the refereed proceedings of the Second International Conference on Distributed Computing in Sensor Systems, DCOSS 2006, held in San Francisco, California, USA, June 2006. The book presents 33 revised full papers, focusing on distributed computing issues in large-scale networked sensor systems. Coverage includes topics such as distributed algorithms and applications, programming support and middleware, data aggregation and dissemination, security, information fusion, lifetime maximization, and localization.