The conductivities of all the currently reported conducting polymers are compared to those of the classical metals. The requirements for a technologically useful conducting polymer are considered and the degree to which existing conducting polymers meet these requirements is evaluated. The mechanism of doping is discussed together with the final state of the dopant and the polymer. The available structural data are described as well as the problems of structurally characterizing these systems. Some of the problems of inhomogeneous distribution of dopant species are also pointed out.