Fifteen years after the publication of Weiser s seminal paper in Scientific American, ubiquitous computing is a large, thriving field of academic research and commercial innovation. The proceedings of the 8th International Conference on Ubiquitous C- puting reflect the strength, diversity and vigor of the research program that Weiser initiated. We hope that you will find much in the papers contained herein to stimulate new and exciting work as we reach forward toward ubiquitous computing together. The location of the conference, in Orange County, California, was particularly - posite given...