A Practical Approach to Recognizing Physical Activities -- Building Reliable Activity Models Using Hierarchical Shrinkage and Mined Ontology -- “Need to Know”: Examining Information Need in Location Discourse -- Collaborative Localization: Enhancing WiFi-Based Position Estimation with Neighborhood Links in Clusters -- Risks of Using AP Locations Discovered Through War Driving -- Declarative Support for Sensor Data Cleaning -- Detecting and Interpreting Muscle Activity with Wearable Force Sensors -- The Design of a Portable Kit of Wireless Sensors for Naturalistic Data Collection -- The Smart Tachograph – Individual Accounting of Traffic Costs and Its Implications -- Domino: Exploring Mobile Collaborative Software Adaptation -- Keep Your Eyes on the Road and Your Finger on the Trigger – Designing for Mixed Focus of Attention in a Mobile Game for Brief Encounters -- Unobtrusive Multimodal Biometrics for Ensuring Privacy and Information Security with Personal Devices -- LoKey: Leveraging the SMS Network in Decentralized, End-to-End Trust Establishment -- Scalability in a Secure Distributed Proof System -- Secure Mobile Computing Via Public Terminals -- iCAP: Interactive Prototyping of Context-Aware Applications -- iCam: Precise at-a-Distance Interaction in the Physical Environment -- Gesture Signature for Ambient Intelligence Applications: A Feasibility Study -- Exploring the Effects of Target Location Size and Position System Accuracy on Location Based Applications -- Displays in the Wild: Understanding the Dynamics and Evolution of a Display Ecology -- Modeling Human Behavior from Simple Sensors in the Home -- Using a Live-In Laboratory for Ubiquitous Computing Research -- The Diet-Aware Dining Table: Observing Dietary Behaviors over a Tabletop Surface -- Lessons for the Future: Experiences with the Installation and Use of Today’s Domestic Sensors and Technologies.