Precise determination of the conductivity exponent of 3d percolation   using "Percola"
  Using 20 months of CPU time on our special purpose computer ``Percola'' we determined the exponent for the normal conductivity at the threshold of three-dimensional site and bond percolation. The extrapolation analysis taking into account the first correction to scaling gives a value of $t/\nu = 2.26\pm 0.04$ and a correction exponent $\omega$ around 1.4. 
J.M. Normand and H.J. Herrmann