carl, this came about yesterday. i bought a new digital camera and some of the first shots were taken on an overcast day. the sky was pretty bland, almost nearly, completely a dull white. so, i loaded up FF, loaded up that image and just built the filter for that image. it's pretty simplistic, but shld work on any image where most or all of the white is in the sky. if you've got other areas of the image that are blown out white, why, this wont work very well for those. but, you could always run FF from another application with masking on your layer and do just the sky that way.
it's really nothing very much, just a perlin noise with some color and then some masking to isolate a white sky and some blending. but, for bland, nearly all white skys, it shld do the trick.
If wishes were horses... there'd be a whole lot of horse crap to clean up!
Craig