  We describe a novel phenomenon occurring when a polarized Gaussian beam of
light is observed in a Cartesian reference frame whose axes are not parallel to
the direction of propagation of the beam. Such phenomenon amounts to an
intriguing spin-dependent shift of the position of the center of the beam, with
manners akin to the spin Hall effect of light. We demonstrate that this effect
is unavoidable when the light beam possesses a nonzero transverse angular
momentum.
