We're so excited by the internet and mobile phones that we forget we have bodies that travel. This path-breaking book shows how people have become networked individuals, expanding the space and diversity of their personal connections. It goes way beyond standard travel-demand studies. Brilliant, well researched, and carefully documented, it rewards quick reading and detailed study. Barry Wellman, University of Toronto, Canada I will be notifying my own professional social network about this timely book, rich in implementation detail and descriptions of best practices. It brings the vital considerations of space and travel to the study of social networks, and those of social interaction to the study of travel behavior. A must-read for anyone interested in either field, and an important catalyst for greater cross-fertilization between the two. Patricia L. Mokhtarian, Georgia Institute of Technology, USA