Microwave Kinetic Inductance Detectors are a new cryogenic detector being developed at Oxford which operate from far infrared to X-rays. They can measure the energy of individual photons to within a few percent and the arrival time to a few microseconds, essentially removing the requirement for bandpass filters and exposure times. Their high sensitivity with essentially no read-noise and simple design means they are the ideal detector for a range of astronomy observations including exoplanets, dark matter detection, and CMB polarizations.