General relativity provides our best description of gravitation in modern physics - currently all observations and tests of gravitational theories have agreed with it. GR is applied in fields as diverse as fundamental astronomy, astrophysics, geodesy, physics, and space sciences, where high-accuracy observations and measurements are taken or modeled. IAU Symposium 261 summarizes the present state of applied relativity. It considers the applications of general relativity in a wide range of disciplines: geodesy, navigation, solar system ephemerides, space missions, pulsar timing, high-accuracy astrometry, gravity waves, gravitational lenses, and black hole astrophysics. The future tests of general relativity based on improved observational accuracies and higher order developments of the theory are discussed in general. Specific projects designed to test the theory in the near future are also covered. This volume is a useful resource for all those interested in general and special relativity, their current applications and future tests.