Breakthroughs in numerical relativity (around 2005) have allowed a tremendous progress in solving the two body problem in general relativity. It is now possible to follow the inspiral, merger and ringdown phases of a binary black hole spacetime, extract accurate wave forms for the gravitational radiation emitted and learn new phenomena, like black hole kicks. It has also been possible to study high energy black hole scattering, and obtain the ratio of energy converted into gravitational radiation and the cross section for black hole formation. In this talk I shall describe the very first steps to apply the same type of techniques to high energy physics scenarios suggested by string theory: namely TeV gravity, the AdS/CFT duality and the study of the non-linear evolution of higher dimensional unstable black hole spacetimes.