  Letting the mass depend on the spin-field coupling as
$M^2=m^2-(eg/2c^2)F_{\alpha\beta}S^{\alpha\beta}$, we propose a new set of
relativistic planar equations of motion for spinning anyons. Our model can
accommodate any gyromagnetic ratio $g$ and provides us with a novel version of
the Bargmann-Michel-Telegdi equations in 2+1 dimensions. The system becomes
singular when the field takes a critical value, and, for $g\neq2$, the only
allowed motions are those which satisfy the Hall law. For each $g\neq2,0$ a
secondary Hall effect arises also for another critical value of the field. The
non-relativistic limit of our equations yields new models which generalize our
previous ``exotic'' model, associated with the two-fold central extension of
the planar Galilei group.
