The SAINT 2006 Workshops address issues related to Internet technology, computing, architecture, software, internetworking, services, and applications. The four 2006 workshops are: IPv6: Deployment of Technologies and Applications, RFID and Extended Network; Deployment of Technologies and Applications, Next Generation Service Platforms for Future Mobile Systems, Ubiquitous Networking and Enablers to Context-Aware Services. The Workshop papers reveal the importance of Internet computing, technologies, software, services, and applications. These papers provide an interesting and complete view of the state of the art in the research activities, and should be a valuable reference for years to come.