Thanks. I have considered using a marquee for the twirl but that does not get at what I really want( at least I don't think so).  the marquee technique would limit the twirls affect to the selection size plus any feather that might be applied.  I was looking for  the ability to affect the whole image but have the center point of the twirl ( the twirl axis) be in the corner of the image rather than the center.  I suppose if I made the feather large enough I could affect the whole image, but I am assuming the affect of the twirl would diminish the further it got from the original selection.   Still, the feather technique might be an acceptable workaround.

You might think "what a cheesy effect", but i work a lot in 3d and sometimes have to build my own texture maps so these techniques will be used more as displacement and bump maps.  As for the rectangle question:  I wish to build some textures for gingham type cloths to use in a a particualr 3d project I am working on.

The rectangle repitetiton technique you mention, Tantarus, sounds just like what I was looking for and will give it a try.  Thank you both.

And beware.  Will return soon return with more annoying questions.