There is a significant need for new devices and architectures for the third era of computing namely, cognitive computing. Nanoscale resistive memory devices such as phase change devices could play a key role in this respect. The phase change devices exhibit a rich dynamic behavior governed by an intricate feedback interconnection of electrical, thermal and structural dynamics. In this talk, I will introduce these fascinating new devices and provide an overview of some of the recent insights we have gained on the structural dynamics such as crystal growth and structural relaxation. Subsequently, a few emerging applications of these devices in the space of memory and computation will be presented. I will conclude with a brief overview of some recent advances in the technological front for these devices.