  We discuss the cosmological evolution of a scalar field with non standard
kinetic term in terms of a Renormalization Group Equation (RGE). In this
framework inflation corresponds to the slow evolution in a neighborhood of a
fixed point and universality classes for inflationary models naturally arise.
Using some examples we show the application of the formalism. The predicted
values for the speed of sound $c_s$ and for the amount of non-Gaussianities
produced in these models are discussed. In particular, we show that it is
possible to introduce models with $c_s^2 \neq 1$ that can be in agreement with
present cosmological observations.
