Depending on how you can bend it, construction of Alcubierre fields allows faster-than-light travel. If you can bend it really precisely, even wormhole construction might not be out of the question. On a lower scale, star trek like forcefields and "perfect" cloaking fields would be possible by bending all light/force carrying particles around an object.
If you looked at it head on and something was in a bubble deflecting light around it, could you tell that it's there because that light takes longer to get through/around relative to the immediate surrounding. Probably still not perceptible.
One of the fun ones would be communicating via gravity wave, also it make the Alcubierre "warp drive" possible.