  We consider T-invariant spin currents induced by spin-orbit interactions
which originate from the confined motion of spin carriers in nanostructures.
The resulting Thomas spin precession is a fundamental and purely kinematic
relativistic effect occurring when the acceleration of carriers is not parallel
to their velocity. In the case, where the carriers (e.g. electrons) have
magnetic moment the forces due to the electric field of the spin current can,
in certain conditions, exceed the van der Waals-Casimir forces by several
orders of magnitude. We also discuss a possible experimental set-up tailored to
use these forces for checking the existence of a nonzero anomalous magnetic
moment of the photon.
