  It is becoming widely recognized that, contrary to earlier expectations, the
usual one-band Hubbard model does not give an explanation for itinerant
ferromagnetism. After reviewing the status of magnetic ordering in the one-band
model, we discuss the possibility of ferromagnetism in some recently introduced
two-band Hubbard models, and in generalized Anderson lattices. It is argued
that these two classes of models are closely related and that it is their
common feature that the ferromagnetic phase has to compete with a collective
Kondo state.
