  The conventional weak-coupling expansion for the pressure of a hot plasma
shows no sign of convergence unless the the coupling constant $g$ is tiny. In
this talk, I discuss screened perturbation theory (SPT) which is a
reorganization of the perturbative expansion by adding and subtracting a local
mass term in the Lagrangian. We consider several different mass prescriptions,
and compute the pressure to three-loop order. The SPT-improved approximations
appear to converge for rather large values of the coupling constant.
