  We present the first lensing mass measurements of Sunyaev-Zel'dovich (SZ)
selected clusters. Using optical imaging from the Southern Cosmology Survey
(SCS), we present weak lensing masses for three clusters selected by their SZ
emission in the South Pole Telescope survey (SPT). We confirm that the SZ
selection procedure is successful in detecting mass concentrations. We also
study the weak lensing signals from 38 optically-selected clusters in ~8 square
degrees of the SCS survey. We fit Navarro, Frenk and White (NFW) profiles and
find that the SZ clusters have amongst the largest masses, as high as 5x10^14
Msun. Using the best fit masses for all the clusters, we analytically calculate
the expected SZ integrated Y parameter, which we find to be consistent with the
SPT observations.
