Practical Modeling of Large-Scale Galactic Magnetic Fields: Status and
  Prospects
  This is a review of the status of efforts to model the large-scale Galactic
magnetic field (GMF). Though important for a variety of astrophysical
processes, the GMF remains poorly understood despite some interesting new
tracers being used in the field. Though we still have too many models that
might fit the data, this is not to say that the field has not developed in the
last few years. In particular, surveys of polarized dust have given us a new
observable that is complementary to the more traditional radio tracers, and a
variety of other new tracers and related measurements are becoming available to
improve current modeling. This paper reviews: the tracers available; the models
that have been studied; what has been learned so far; what the caveats and
outstanding issues are; and one opinion of where the most promising future
avenues of exploration lie.
