  We consider thin superconducting (S) films of thickness d $\ll \xi_{0}$,
sandwiched between two ferromagnetic semiconducting insulators (FI) with
differently orientated magnetizations - the FI-S-FI system. We calculate the
dependence of the superconducting critical temperature on the orientation of
the magnetization in the insulators and on the thickness of the superconducting
film. The calculations are done for singlet as well as triplet superconductors.
In the singlet case T_{c} depends on the relative orientation of the left and
right magnetization only, while in the triplet case T_{c} depends on the
absolute orientation of magnetization. The latter property can serve as a kind
of spin-spectroscopy of triplet and unconventional superconductors, for
instance in resolving the structure of the triplet order parameter in the
recently discovered layered superconductor Sr_{2}RuO_{4}. The possibility of
logic circuits and switches, which are based on the FI-S-FI systems with
arbitrary orientation of magnetizations in FI films, is analyzed too.
