Basically, what Greycstoration algorithm does is describe how to do noise reduction and scaling of images very well. It also does a hell of a lot more and the demo page is very impressive!
There’s a GIMP plugin based on the work but I couldn’t get it to compile. He has another demo page too, which leads me to believe that I will spend some time trying to get this to work!
Later.. Note to self, install the development libraries before complaining!
# apt-get install libgimp2.0-dev