Abstract: This talk highlights the potential of sensor-based interaction for mobile devices. The integrated camera, for example, can be used to support information navigation on handheld devices, which is characterized by small display dimensions and limited input capabilities. Special strategies are required to help users to navigate to off-screen content and to understand spatial layouts. Yet, handheld devices offer ways of interaction that desktop computers do not. They can easily be moved in space and serve as a window into a large virtual workspace. I will present different information navigation methods for small-scale handheld displays that use various sensor technologies for spatial tracking. A two-component Fitts' law extension for magic lens pointing will be discussed that is relevant for handheld augmented reality applications in which a camera-equipped device is tracked in front of a large-scale surface. Moreover, I will present a system in which stationary cameras track t! he spatial arrangement of multiple devices on a table, which can be applied in coordination tasks within a group of collocated people.