While searching to create an image of my customized SD card I found this post. The best answer here discusses imaging the SD card, but what I was looking for required shrinking down the filesystem to make the image as small as possible. I ended up creating my own tool to do this and outline the process at: http://raspberrypi.stackexchange.com/a/37899/32585https://raspberrypi.stackexchange.com/a/37899/32585