Evidence from radio polarization measurements is reviewed that indicates that most galactic magnetic Field structures fall into one of two categories: axisymmetric spiral and bisymmetric spiral. The resultant challenges to dynamo theorists is stated. Estimates of the magnetic field strengths based on equipartition of field and cosmic ray energies are given, but deviations from equipartition are inferred. Possible goals for future research are suggested. © 1990, Taylor & Francis Group, LLC. All rights reserved.