Beaver,
Cast iron can be used just like wrought iron, brass or anything else. Unlike wrought iron, if you intend to etch it, it won't have those interesting long grain patterns like the wrought stuff does. The grain is extremely uniform and large from the casting process. So etching usually shows up as a bunch of round shapes.
Other than that it will work a lot like aluminum except it's more brittle and will take bluing. Oh, it doesn't like to be bent or heated and beat on much either.
Sorry, no pics. Karl Anderson just posted some pics of some wrought iron fittings a while back. Only difference is the way it's produced. Cast vs drawing.