  Models of hierarchical galaxy formation predict that large numbers of
low-mass, dark matter halos remain around galaxies today. These models predict
an order of magnitude more halos than observed stellar satellites in the Local
Group. One possible solution to this discrepancy is that the high-velocity
clouds (HVCs) around the Milky Way may be associated with the excess dark
matter halos and be the gaseous remnants of the galaxy formation process. If
this is the case, then analogs to the HVCs should be visible in other groups.
In this paper, we review the observations of HI clouds lacking stars around
other galaxies and in groups and present early results from our HI survey of
loose groups analogous to the Local Group and its implications for the nature
of HVCs and galaxy formation.
