The entropy difference between a liquid and one of the glasses that it samples is called the configurational entropy, S-c, and it may provide an important link between dynamic and thermodynamic measures of the fragility of liquids. Most previous estimates of S-c have implicitly assumed that all glasses of the same substance have the same entropy, but that assumption can lead to estimates of S-c and its temperature dependence that may be wrong by a factor of 2 or more. New estimates of S-c for toluene and ethylbenzene are used to test relations between thermodynamic and kinetic measures of fragility implied by Adam and Gibbs theory.