We have derived a surface-area-based version of the generalized Born model (S-GB) as a well-defined approximation to the boundary element formulation of the Poisson-Boltzmann (PB) equation. The relationship of the surface area methodology to the volume-integration-based approach of Still and co-workers is elucidated. On the basis of insights obtained from these results, we then develop empirical correction schemes which yield significant improvements in accuracy, as compared to the uncorrected GB model, in reproducing accurate solutions of the Poisson-Boltzmann equation. A large suite of energetic comparisons of GB, corrected S-GB and PB for multiple conformations of peptides and proteins is presented.