Likewise, it's tough to pick out a single 20 kilometer wide neutron star in the vast reaches of space. Gravitational waves would, however, describe exactly what those crazy remnants are doing. Black hole theories are pretty sketchy as it is, and no one's really sure what happens when two black holes collide such as they would in a binary. What I gave was just a guess. A lot of guesses about black holes and neutrons stars would be verified or rejected if we could just learn more about them.
Gravitational waves are a great way to do that.
It takes so much energy and mass to generate gravitational waves that it is quite inconceivable that humans could do it. The ones who stand to gain from the detection of gravitational waves are the astronomers and astrophysicists. New theories would rise and fall on gravitational waves and what they would tell us about the universe. As always, there will be improvements in materials science and signals science that occure during the attempt to detect these waves. Hey, the whole space project developed that fantastic material we call plastic.