Pulsars are neutron stars that are formed in supernova explosions following the collapse of massive evolved stars. These exotic objects are more massive than the Sun and can spin over 700 times a second. They have extremely high magnetic fields - over a trillion times the Earth's! These properties make them energetic sources of radio waves, which are beamed along their magnetic axes. We detect a "pulse" of radio emission once every pulsar rotation period, in a similar manner to a lighthouse. The rotation periods of pulsars can be measured incredibly precisely, making these "cosmic clocks" excellent laboratories for fundamental physics experiments. In this lecture, I will give an overview of pulsars and their properties, and describe several recent highlights of pulsar research, including our search for gravitational waves from the most massive black holes in the universe.