The importance of phonons has long been recognized by research ers in nonequilibrium superconductivity. Similarly, experimentalists studying phonons at low temperatures have relied heavily on supercon ductors as sources and detectors. To a large extent this symbiotic relationship has developed with a general mutual awareness; however, to our knowledge these subjects have never been treated together in conferences or study institutes. It was with the hope of further contributing to the awareness and communication between workers in these areas that this NATO Advanced Study Institute (ASI) has...