By adjustment of the optical pathlengths of the MMT telescopes, it is possible to make the MMT into a phased array with a 680 cm baseline. We will describe experiments in speckle interferometry and spectroscopy which have been done this way using 2 and 3 of the MMT telescopes. We will describe planned adjustments of the optical configuration of the MMT to achieve coherent operation over a large field of view with all six telescopes phased simultaneously.