  We present a microscopic theory of transport in quasi-periodically driven
environments (`kicked rotors'), as realized in recent atom optic experiments.
We find that the behavior of these systems depends sensitively on the value of
Planck's constant $\tilde h$: for irrational values of $\tilde h/(4\pi)$ they
fall into the universality class of disordered electronic systems and we derive
the microscopic theory of the ensuing localization phenomena. In contrast, for
rational values the rotor-Anderson insulator acquires an infinite (static)
conductivity and turns into a `super-metal'. Signatures of the corresponding
metal/super-metal transition are discussed.
