Large aperture GPS networks have provided revolutionary views of the Earth's surface in motion and provide the fundamental observations for understanding the nature of continental deformation. We have developed linear block modeling theory to interpret these measurements in active tectonic environments from Tibet to Japan and southern California. Block theory allows for the simultaneous imaging of fault slip rates, micro-plate rotations, fault coupling, and off-fault deformation decomposing complex GPS velocity fields into their constituent tectonic elements. These methods provide high-resolution images of fault systems in motion allowing us to answer questions about the nature of continental deformation: How do fault systems coordinate motion to partition slip across plate boundary zones? How complex are fault systems and how can we understand fault interactions within them? What processes are most important for controlling the long-term evolution of fault networks? Where are large earthquakes most likely to occur in the future?