  Combining pairs of ferromagnetic metals with different signs of scattering
anisotropies, let us independently invert the magnetoresistance and the
direction of current-driven switching in
ferromagnetic/non-magnetic/ferromagnetic metal nanopillars. We show all four
combinations of normal and inverse behaviors, at both room temperature and
4.2K. In all cases studied, the direction of switching is set by the net
scattering anisotropy of the fixed (polarizing) ferromagnet. We provide simple
arguments for what we see.
