  We explore the impact of weak disorder on the dynamics of classical particles
in a periodically oscillating lattice. It is demonstrated that the disorder
induces a hopping process from diffusive to regular motion i.e. we observe the
counterintuitive phenomenon that disorder leads to regular behaviour. If the
disorder is localized in a finite-sized part of the lattice, the described
hopping causes initially diffusive particles to even accumulate in regular
structures of the corresponding phase space. A hallmark of this accumulation is
the emergence of pronounced peaks in the velocity distribution of particles
which should be detectable in state of the art experiments e.g. with cold atoms
in optical lattices.
