The Ubiquitous Computing conference series provides the premier forum in which to present original research results in all areas relating to the design, implementation, app- cation and evaluation of ubiquitous computing technologies. It is a well-established platform to introduce and discuss research that enables new capabilities, appropriate security and privacy, improved user experiences and simplified and powerful devel- ment and deployment practices. These proceedings contain the papers presented at the Ninth International Conf- ence on Ubiquitous Computing (UbiComp 2007) in Innsbruck,...