We wish to create robotic systems capable of autonomously changing shape in order to match the system’s structure to the task at hand. Many interesting robotic systems have been proposed in pursuit of this goal. Our newest approach is based on the, the novel M-Block, a magnetically-bonded, angular momentum-actuated modular robot. These 50mm cubes are autonomous robots that have no external actuated moving parts, and no tethers. The modules realize pivoting using inertial force actuation. A flywheel located inside the module, (oriented in the plane of the intended motion), is used to store angular momentum before a braking mechanism is used to decelerate the flywheel and, during a short duration, exert a high torque on the module. If this torque is sufficiently high, the module breaks its magnetic bonds with its neighbors and pivots into a new location.