This book provides current research on social networking. The first chapter presents an application of network analysis to characterize the role of the Information and Communication Technologies (ICT) sector as an enabler of knowledge and innovation diffusion across the economy. Chapter Two proposes a novel algorithm for computing the similarity of users in a social network considering their characteristics. Chapter Three addresses both the modeling of information dissemination, especially via epidemics and evolutionary game theoretic techniques, as well as their control via optimal control frameworks and dual optimization techniques. Chapter Four is designed to explore socially networked spaces as an important process within teacher professional development. Social networking enables teachers to access new ideas, to collaborate and to contribute to a shared knowledge, regardless of time and place.