  We discuss the implementation of the ``direct'' maximal center gauge (a gauge
which maximizes the lattice average of the squared-modulus of the trace of link
variables), and its use in identifying Z(2) center vortices in Yang-Mills
vacuum configurations generated by lattice Monte Carlo. We find that center
vortices identified in the vacuum state account for the full asymptotic string
tension. Scaling of vortex densities with lattice coupling, change in vortex
size with cooling, and sensitivity to Gribov copies is discussed. Preliminary
evidence is presented, on small lattices, for center dominance in SU(3) lattice
gauge theory.
