The outer parts of spiral galaxies are interesting in several ways --
because the dark matter is found there, because the outer disks
control the future of star formation in a galaxy, and because it is a
new environment in which to study star formation and the formation of
molecular clouds.  The main focus of my presentation will be on the
interstellar medium: its mass, the phases present (ionized, atomic,
and molecular), and the relationship with star formation in the
low-metallicity low-radiation field environment of outer disks.