This book constitutes the refereed proceedings of the 7th International Conference on Ubiquitous Computing, UbiComp 2005, held in Tokyo, Japan in September 2005.

The 22 revised full papers presented were carefully reviewed and selected from 230 submissions. The papers address topics related to human-computer interface (HCI), systems, context recognition and use, communications, and social implications and applications of computing. Methodologies included real-world deployments, laboratory experiments, ethnographic analysis, qualitative and quantitative evaluation, and theoretical explorations. Topics of special interest are location systems and their applications, case studies and user interfaces, algorithms for recognition of context, and novel devices.