  Experimental evidence from RHIC indicates that matter having an energy
density far in excess of the value required for the creation of a deconfined
phase is produced in ultrarelativistic Au+Au collisions at a center of mass
energy of 200 GeV. This matter thermalizes rapidly, is strongly interacting,
and displays hydrodynamic properties akin to a fluid with very low viscosity.
Studies of the interaction of hard scattered partons with this matter provide
an important probe of its properties. In fact, studies of the suppression of
high-p_T hadrons have been one of the key arguments used by the RHIC
experiments that the matter created is something fundamentally new and
exciting. I review the current experimental picture that has emerged from the
data collected at RHIC, with an emphasis on the effort to extract quantitative
measurements from the suppression of high-p_T hadrons.
