Simple point-charge models are used widely to provide effective condensed phase potentials in computer simulations of water. Yet, recent studies have demonstrated that explicit inclusion of polarizability can significantly improve the model. We discuss a simple model which explicitly incorporates results from ab initio studies of the water molecule in applied electric fields. The polarization response, parameterized in terms of the local field, is incorporated into the positions and/or values of the three site charges of the model. The importance of non-linearity in the response is examined. The structural, thermodynamic, and dielectric properties of model systems, both under normal and extreme conditions, are reported. We also compare second and third virial coefficients for several water models with experimental data.