Are astronomers already looking for these structures? I thought that we had images in some kind of wavelength of light of distant black holes. Or was it simply detecting their presence from light-bending and I'm smoking crack?
I don't know if you're smoking crack or not, but black holes are detected by light bending and x-ray emission. This is from 2013, which some interesting imaging suggesting black holes would look like crescent shapes:
http://www.space.com/19324-black-holes-first-images.html And this from hubblesite.org: What does a black hole look like?
A black hole itself is invisible because no light can escape from it. We can't see black holes, but we can find them by examining their effects on objects around them.
We identify suspected supermassive black holes in the center of galaxies by studying the orbits of stars and clouds of gas in that vicinity and the speed with which they move. If those motions indicate the presence of more mass than can be accounted for by counting the stars in that area, the best explanation for the extra mass is a black hole.
When a smaller black hole and a star orbit each other, the black hole can be identified if it pulls matter from its companion star. As the matter swirls into the black hole it heats up, emitting x-rays that can be detected by astronomers.
The best takeaway is a summary of your last paragraph: What black holes "look" like is primarily determined by their surroundings. There are other intrinsic properties of a black hole (mass/size, spin, and charge) that will affect appearances, though not as much as surroundings. In the picture produced by the "Interstellar" simulation, it looks like they've simulated a more or less symmetric/homogenous accretion disk.This is from 2013, which some interesting imaging suggesting black holes would look like crescent shapes: http://www.space.com/19324-black-holes-first-images.html