I'm reading a fairly technical paper that shows that rotating superconductors may affect gravity fields[pdf].
...a clear azimuthal acceleration, which could be associated with an anomalous gravitational field, directly proportional to the superconductive ring angular acceleration, and an angular velocity orthogonal to the ring’s equatorial plane, which could be associated with an anomalous gravitomagnetic field, have been measured in type-(1) and type-(2) experiments respectively...This is pretty big if true. It means we will some day figure out how to make gravity generators. Or possibly even gravity nullifiers. At least on a small scale.