Grunge River

As you can see, I'm continuing my love affair with grunge effects.
In Gimp, the following will give you this effect:
1. Import an image that is slightly over-exposed. I photograph in RAW and use ufraw to import, so I can change the exposure pretty easily.
2. Duplicate the base layer, blur it up and then desaturate it. Set mode of this new layer to Multiply. This gives a nice slightly desaturated, softened effect.
3. In a third layer, render some random clouds (Plasma in Gimp) and desaturate again. Set this grunge layer to Multiply Mode as well.
4. Add a layer mask to the grunge layer, and paint out the centre of the image.
5. Add a white signature brush-stroke.
End result is as above.