  We study the effects of quenched height fluctuations (ripples) in graphene on
the density of states (DOS). We show that at strong ripple disorder a
divergence in the DOS can lead to an ordered ground state. We also discuss the
formation of dislocations in corrugated systems, buckling effects in suspended
samples, and the changes in the Landau levels due to the interplay between a
real magnetic field and the gauge potential induced by ripples.
