They propagate at the speed of light and are not altered by the matter through which they pass. They affect the stuff they pass through by alternately compressing and rarifying things. Yeech, that didn't make much sense. These guys would be unique and identifiable by their signatures and would give a wealth of information about their current status. Binaries are more fun because they're slighty easier for the earth-based detectors to find and because they're not just sitting still like lumps.
Binaries do fun stuff like rotate and inspiral.
The detection of a gravitational wave would verify once 'n' for all and without a doubt the existence of black holes, and there are no few people currently developing detectors of all sorts. I should explain the table a bit. In the Galaxy column you'll find the name of the host galaxy, the place where the black hole is. Some objects belong to both systems. The Comment column gives anything of note of that particular object, such as a common name or the location.