  In this article I review recent observations of the gaseous halos of galaxies
and the intergalactic medium at low redshift. In the first part I discuss
distribution, metal content, and physical properties of the Galactic
intermediate- and high-velocity clouds and the hot halo of the Milky Way.
Recent absorption and emission measurements show that the Galaxy's tidal
interaction with the Magellanic Clouds, the infall of low-metallicity gas, as
well as the circulation of gas as part of the galactic fountain contribute to
the observed distribution of gas in the halo of the Milky Way. In the second
part I give a short overview on the circumgalactic gaseous environment of other
nearby spiral galaxies. Multi-wavelength observations demonstrate that neutral
and ionized gaseous halos of galaxies are common, and that they extend deep
into intergalactic space. These studies suggest that the gaseous material
around spiral galaxies is tightly connected to the on-going hierarchical
formation and evolution of these galaxies. In the last part of this article I
summarize recent quasar absorption-line measurements of the local intergalactic
medium. In accordance with cosmological simulations, absorption-line studies in
the far-ultraviolet indicate that both the photoionized Ly alpha forest and the
shock-heated warm-hot intergalactic medium harbor a substantial fraction of the
baryons in the local Universe.
