Can gravity be used as a communication tool?

Are there any scientific evidence out there that gravity could be potentially used as a communication tool of the future? If such a tool had existed it would unable(supposed to be "enable"?) communication faster the speed of light...in fact it would seem that it would be instant regardless of the distance). Any ideas? Thanks!

Hmmm... Well, I guess if you managed to modulate your data onto a gravity wave you could transfer it that way, but i guess that would need a system that could, at least partly shield gravity or increase gravity to create the carrier and modulate the data onto it, or perhaps you could play with a couple of black holes, but i don't se how you could impress your data at any usable speed(if at all) at something of that mass... Anyway, the data would still not move faster then light, as far as I know, gravity field propagation is limited to c...

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