In this colloquium I will talk about new methods that we are developing
to determine the dark matter distributions in disk galaxies. One of
these methods focusses on the relationship between spiral arm pitch
angle (the measure of how tighly wound spiral structure is) and rotation
curve shear (a dynamical measurement reflecting the slope of the
rotation curve). I will show some examples as to how this can be used to
place constraints upon dark matter density profiles. I will also discuss
two major projects, the Arkansas Galaxy Evolution Survey (AGES) and the
Carnegie-Irvine Nearby Galaxies Survey (CINGS) and how these projects
can be used to determine dark matter distributions, and the possibility
that dark matter central densities play a role in supermassive black
hole masses.