Talks about mobile communication use in Japan, covering the transformation of keitai (Japanese term for mobile phone) from business tool to personal device for communication and play. This book contains essays that document the emergence, incorporation, and domestication of mobile communications in a range of social practices and institutions.

Some essays suggest that the use of mobile communication reinforces ties between close friends and family, producing "tele-cocooning" by tight-knit social groups. The book also discusses mobile phone manners and examines keitai use by copier technicians, multitasking housewives, and school children. "Personal, Portable, Pedestrian" describes a mobile universe in which networked relations are a pervasive and persistent fixture of everyday life.