  A complete description of W and Z boson production at high-energy hadron
colliders requires the resummation of large Sudakov double logarithms which
dominate the transverse momentum (q_T) distribution at small q_T. We compare
different prescriptions for performing this resummation, in particular implicit
impact parameter space resummation versus explicit transverse momentum space
resummation. We argue that the latter method can be formulated so as to retain
the advantages of the former, while at the same time allowing a smooth
transition to finite order dominance at high q_T.
