It is always convenient to raise something you don't quite understand to the status of a Principle. Mach's Principle seems to be a case in point; over the years it has greatly puzzled many Physicists and Philosophers. It certainly still puzzles me. Perhaps this forum can dispel some of my confusions. As I understand it, Mach's Principle (MP) seems to attribute inertial mass to a quite unknown species of integrated action-at-a-distance, originating from all the matter in the universe. Mixed up with this principle is the idea that the "fixed stars" provide a preferred frame of reference, against which acceleration and rotation can be gauged. From a modern perspective Mach might have preferred to replace Newton's reference frame of absolute space, long out of fashion, with a frame co-moving with the galaxy clusters of the Hubble flow. Such a frame would now be set in the context of General Relativity, (GR), although MP is not thought to be a consequence of GR. Nevertheless it has a "global' (as distinct from "local") flavour in the relativistic sense. General Relativity teaches that all inertial reference frames are equivalent. But from a local perspective it is now clear that there is one local inertial frame that can be picked out from the infinite number of such physically equivalent local frames. This is the frame at rest with respect to the Cosmic Microwave Background (CMB). From a local perspective this CMB frame restores Newton's absolute reference frame, but without imposing the restrictions of Galilean coordinate tranformations. From a global perspective there is no single (non co-moving) CMB frame. CMB frames, like the one we are coasting through at about 600 km/sec, are a local concept. Each locality, equipped with its infinite set of inertial frames, has its own unique local CMB frame that (in a model FRW universe) strictly follows the Hubble flow. George Orwell might have claimed that this inertial frames is more equal than the rest! I would like to ask: The CMB is thought to have been the photonic component of all mass/energy at decoupling; i.e. before gravitational condensation coagulated the universe. Could it, acting as a marker for all mass/ energy in the universe, somehow determine inertia and permit us to gauge acceleration and rotation? Or are we past such ideas? Is it possible that Mach was in a sense right after all?