The main tool used in creating these sorts of images is a photoshop filter by Mario Klingemann called Extractor 1. It only has four sliders in it and the outcome is a literally, black and white image containing just two colors. This simple filter combined with the sierpinski triangle filter called multicrystal.8bf by Ilyich the Toad creates some very intricate images in the most primitive of all digital formats, binary.
An enhanced effect can be had by using Mirror, Mirror, also a photoshop filter, made by Alfredo Mateus. This does nothing more than create a symetrical image (mirrored) however, just like the simple Extractor filter, the results can be quite interesting.
If you're at all familiar with Poe's writing, then you will have undoubtably noticed that the text on the last four images is not his. I wrote it myself after a long frustating search for a quote that would fit one of my images and after reading so much of the original writing I thought I could write the quote I was looking for.