  I review observational data on the kinematic properties of dwarf spheroidal
galaxies in the halo of the Milky Way and beyond. The present data confirm
previous claims that these galaxies have unusually large central velocity
dispersions. `Simple' sources of bias such as binary stars, internal
atmospheric motions, measurement errors, and small sample sizes cannot explain
the large dispersions measures in all dSph systems. Recent data suggest that in
some of these dwarfs the veolocity dispersion profiles are flat out to their
classical tidal radii. I discuss how these results can (or cannot) be
understood by invoking a variety of distinct models, including classical dark
matter halos, tidal disruption and MOND.
