  Ongoing accretion of low-metallicity gas onto the disk is a natural
prediction of semi-analytical Galactic chemical evolution models. This star
formation fuel ameliorates the overproduction of metal-poor G- and K-dwarfs in
the solar neighbourhood which otherwise plague so-called ``closed-box'' models
of Galaxy evolution. Do High-Velocity Clouds (HVCs) represent the source of
this necessary fuel? We know that HVCs provide an important clue as to the
processes governing galaxy formation and evolution - what is less clear is
whether their role lies more closely aligned with cosmology (as relics of the
Local Group's formation) or star formation (as tidal debris from nearby
disrupted dwarfs, or the waste byproducts of disk supernova-driven winds). I
provide a summary of recent speculations as to the origins of HVCs, and
highlight several future projects which will lead to a deeper understanding of
the role they play in galaxy evolution.
