Magnetic bearings consist of magnetic poles arranged in a circular configuration in order to levitate a spinning rotor. Since they are non-contact bearings they reduce losses due to friction. In addition, since they are an active control device, they offer excellent opportunities for vibration control. Currently, high costs and technological limits have prevented their widespread use. They represent a challenging problem to a dynamicist since a proper design involves a melding of electromagnetic theory, electronics, control systems and rotor dynamics. We have been working on several aspects of magnetic bearings and have also managed to build one with a grant from ONR. Some of the projects underway or completed are listed below.