In the last few years a new regime of thermonuclear burning on neutron stars has been discovered. This new regime manifests itself through the production of hours long flares with a recurrence time on the order of years. These flares are now commonly referred to as ``superbursts." Their discovery was made possible by sensitive, long term monitoring of the X-ray sky with the BeppoSAX Wide Field Cameras (WFC) and the RXTE All Sky Monitor (ASM). I will discuss the current observational and theoretical understanding of these events, and what they are teaching us about neutron stars and thermonuclear burning on them. I will also discuss recent high time resolution studies of a superburst from 4U 1636-53 with RXTE which showed coherent oscillations at the well known 582 Hz burst oscillation frequency in this source.