I'm not terribly knowledgeable about relativity, but I don't think that gravitational repulsion is a very meaningful concept in GR. I would appreciate being corrected on this matter if that is not true.

> a novelty device that weighs more than what it's mass would lead you to think it weighs

This is an interesting concept. As far as I'm aware, we have ways of measuring weight, but no way of measuring mass. How would you know whether something weighed more than it "should", based on its "mass"?

That sounds like a tractor beam to me.

> I'm pretty sure a graviton generator would just be a novelty device that weighs more than what it's mass would lead you to think it weighs

Which would make space travel a lot easier - no more worrying about bone density loss!

Could such a device be used to increase the reaction mass of your fuel when it exits your engine? A sort of way to cheat F=MA by artificially boosting M, but only after you are in orbit?