This talk describes a new and highly efficient method of measurement and analysis, giving several examples of its application in the field of scanning probe microscopy.  High Q resonators are frequently employed in physics to make sensitive measurements, where the system of interest perturbs the dynamics of the resonator.  Often this perturbation is nonlinear and when driven at two our more frequencies, the resonator responds with a frequency-comb of intermodulation products (frequency mixing products).  With an appropriate drive scheme, many high-order intermodulation products can be measured near resonance with good signal-to-noise ratio.  A remarkably simple method exists for reconstructing the nonlinear perturbation from a phase-coherent measurement of the intermodulation products.  The frequencies must be carefully tuned, or appropriately chosen such all tones in the comb have a definite phase relation to one reference oscillation, thus enabling a multifrequency lockin measurement.