This article is largely incorrect. Gravitons aren't predicted by the General Theory of Relativity. GPS satellites are 1) Useful and 2) Built with control systems that make relativistic corrections to compensate for the curvature of space caused by the earth. Predictions made by relativity which have been verified include: Black Holes, Gravitational Lensing, Spatial Twisting by Rotating Bodies, Extreme Time Distortions Near Black Holes, and Time Dilation by Spatial Curvature.
Gravitational Interferometers are also built to measure the gravity waves that are predicted by the general theory. They also have the inconvenient property of, you know, working.
Thank you, JoshuaZ, for correcting the urban legend. Even most Christians concede Einstein's beliefs resembled a form of Deism. MountainDew 02:56, 5 March 2007 (EST)