The talk presents a review of new developments in metallic, magnetic and superconducting layered heterostructures yielding novel physics phenomena as well as applications. Particular emphasis is given to superconductor-ferromagnet (SF) systems. I consider novel suggestions in field of magneto-electronics, digital and quantum logics like the superconducting (S-F) spin switch, 'self-frustrated' superconducting networks with 'pi-junctions' which may be used for the realization of the superconducting quantum bit and new superconducting 'complementary' electronics. Recent experimental and theoretical results related to observations and investigations of the pi-state and spin-injection effects in the superconductor-ferromagnet systems will be presented.