  Photoproduction spin sum-rules offer a new window on the spin structure of
the nucleon that complements the information we can learn from polarised deep
inelastic scattering experiments. We review the theory and present status of
the Drell-Hearn-Gerasimov sum-rule in QCD, emphasising the possible relation
between the present ``discrepancy'' in this sum-rule and the nucleon's
strangeness magnetic moment. In the case of an elementary electron or photon
target (say at the NLC) the Drell-Hearn-Gerasimov sum-rule provides a test for
physics beyond the minimal Standard Model.
