I will discuss the physics of transport phenomena in
driven chaotic environments (`kicked rotors'), as
realized in recent atom optic experiments. The behavior
of these systems depends sensitively on the value of a 
scaled Planck constant $\tilde h$: for irrational values of
$\tilde h/(4\pi)$ they fall into the universality class of
disordered electronic systems and I will discuss the corresponding
localization phenomena. In contrast, for rational values the
rotor-Anderson insulator acquires an infinite conductivity
and turns into a `super-metal'.  This implies the existence of a novel 
'metal/super-metal' quantum phase transition in cold atom systems.