I had a little free time so I threw this together. The image is a .gif, randomly rotated and repeated a random number of times from 0 to 50. As the layers build, they are enlarged very slightly to provide the illusion of perspective distortion.
Right now between the rotation and the distance offsets there is a lot of moire happening along the edges of the "buildings", but judicious use of blocks of color, and perhaps restriction rotation to 45-degree increments will solve the problem. I also had to add a single transparent pixel all the way around the image when I created it, in order to keep a hair-line from "wrapping" to the opposite side of the image. After all, I am using a fill to create the image, rather than duplicating the image directly. I feel this gives me a lot more control over how it is displayed, and allows for flood-filling large shapes with textures in order to make e.g. a long wall out of a single small brick texture and a lot of large, dynamically created sprite graphics.
Now that I am beginning to load images in a runtime, I have to correct for a security issue when accessing "the network" locally. Flash doesn't want to let the user do that, so when I compile the movie I need to use the "-use-network=false" flag in the mxmlc.exe compiler.
A little more each day. I don't have large chunks of time to spend learning these things, so I need to make the most of, say, half an hour before work, and an hour at night during the week. Such is the life of the obsessive hobbyist.