  We study AdS/CFT with a Kaluza-Klein magnetic field in one plane. By
appropriate choice of magnetic U(1), and by balancing the magnetic field
against the background D field, we obtain a supersymmetric field theory. We
find the dual geometry for an AdS_5 to AdS_3 x R^2 example, and we compare the
moduli spaces and entropies. For the entropy, the interactions are important
even at weak coupling. We also consider nonsupersymmetric embeddings of the
U(1), and show that over a regime of parameter space all known instabilities
appear to be absent, aside from a dilaton tadpole that may be removed in a
number of ways.
