Book excerpt: Social navigation is an emerging field which examines how we navigate information or locate services in both real and virtual environments and how we interact with and use others to find our way in information spaces. It has led to new ways of thinking about how we design information spaces and how we address usability issues, particularly in collaborative, web-based systems. This book follows on from Munro et al, Social Navigation of Information Space, which was the first major work in this field. It provides a similar broad overview of the field, but is much more practical in focus.