In this paper we review some approaches that lead to deviations from t
he well known Brownian motion. We focus on the less explored enhanced
diffusion for which the mean-squared displacement is superlinear in ti
me. Such a behavior appears to be generic in various nonlinear Hamilto
nian systems. We discuss the Levy walk scheme that gives rise to such
enhancement and calculate the corresponding propagators. An applicatio
n to a family of one-dimensional maps is presented.