  Based on a dispersive approach, we apply the inverse amplitude method to
unitarize one-loop SU(2) and SU(3) Chiral Perturbation Theory. Numerically, we
find that this unitarization technique yields the correct complex analytic
structure in terms of cuts and poles. Indeed, using the chiral parameter
estimates obtained from low energy experiments we obtain the poles associated
with the rho(770) and K^*(982) resonances. Just by fixing their actual masses
we obtain a parametrization of the pi-pi and pi-K phase shifts in eight
different channels. With this fit we have then calculated several low-energy
phenomenological parameters estimating their errors. Among others, we have
obtained the chiral parameters and scattering lengths, which can be relevant
for future experiments.
