High-velocity clouds of neutral hydrogen (HVCs) and the satellites which surround our Galaxy trace the accretion and development of our Galaxy and its extended halo. The link between, and content of, these features places important constraints on the simulated dark matter halos in CDM models of the formation of the Local Group. The Magellanic Stream is a clear signature of ongoing satellite accretion by our Galaxy. Are there other examples of almost entirely accreted satellites and yet unaffected satellites hidden under the HVC or compact HVC (CHVC) classification? The nature of the Magellanic Stream will be discussed and the remaining HVCs and CHVCs will be considered in the context of CDM simulations of the Local Group.