One of the most fundamental discoveries in physics and astrophysicswas made with the discovery of pulsars. Ever since, pulsars – andlater in particular binary and millisecond pulsars – have beenstudied as extreme end-states of stellar evolution, as super-denseobjects, as radio and high-energy sources, as probes for theinterstellar medium, and as super-precise clocks for fundamentalexperiments in gravitational physics. This article reviews some of theexciting applications of pulsar physics and the amazing prospects thatare promised by the advent of the Square-Kilometre-Array (SKA).