  We study the effect of magnetic anisotropy in a single electron transistor
with ferromagnetic electrodes and a non-magnetic island. We identify the
variation $\delta \mu$ of the chemical potential of the electrodes as a
function of the magnetization orientation as a key quantity that permits to
tune the electrical properties of the device. Different effects occur depending
on the relative size of $\delta \mu$ and the charging energy. We provide
preliminary quantitative estimates of $\delta \mu$ using a very simple toy
model for the electrodes.
