Torsion-balance tests of the weak equivalence principle
  We briefly summarize motivations for testing the weak equivalence principle and then review recent torsion-balance results that compare the differential accelerations of beryllium-aluminum and beryllium-titanium test body pairs with precisions at the part in $10^{13}$ level. We discuss some implications of these results for the gravitational properties of antimatter and dark matter, and speculate about the prospects for further improvements in experimental sensitivity. 
T. A. Wagner, S. Schlamminger, J. H. Gundlach and E. G. Adelberger
gr-qc hep-ex