This is not directly related to Lattice QCD, but it is interesting nevertheless.
There recently was a public lecture entitled "Was Einstein right?" here at Regina, given by Clifford Will. Unfortunately bad weather meant he couldn't be here in time to give the technical version of this to the physics department, but a printed version of what he probably would have said can be found in this review. It appears that General Relativity is beginning to approach the same kinds of precision in its tests that we know from QED.