I'm not that much of a "psycho-modder" that I would have this kind of thing in my machine, as I see it as a valuable 5.25" Bay slot in the case which could take an extra drive sacrificed, but there are times I think about building a machine that comprises these kinds of devices just for the sheer hell of it. And why not!
More pics here, here, here, and here.
I know that there are other products like this on the market, but this one does it with a little style, producing a heavy duty, almost "hi-fi" look that smacks of power and ass-kickingness. Oh, and it glows in the dark.