Applications involving the utilization of stored flywheel energy are many and varied, ranging from the potter's wheel used in biblical times to present day energy recuperation in automotive vehicles. In general, stored flywheel energy can be used individually or in combination in three ways: (1) by dissipation in overcoming resistances, (2) by exchange to potential energy, and (3) by kinetic transfer to another mass. This last method of utilization offers the greatest potential. Several research and development programs applying this principle are described.