  Interstellar medium is turbulent and this induces relative motions of dust
grains. We calculate relative velocities of charged grains in a partially
ionized magnetized gas. We account for anisotropy of magnetohydrodynamic (MHD)
turbulence, grain coupling with magnetic field, and the turbulence cutoff
arising from the ambipolar drag. We obtain grain velocities for turbulence with
parameters consistent with those in HI and dark clouds. Those velocities are
smaller than those in earlier papers, where MHD effects were disregarded.
Finally, we compare grain velocities arising from photoelectric emission,
radiation pressure and thrusts from molecular hydrogen formation. We conclude
that turbulence should prevent segregation of grains of different sizes.
