Below you can download the files. Here I have made a few charts to let you get a better grasp of the various brushes, well, some of them at least. Don't forget that all files will be put here:
catatonic.dk/public/cornucopia/program-gimp/brushes
The brushes are rather large, but I've added downscaled versions of some of them. Download...
Based on watercolor paint. Download...
Based on pastel colors. Download...
Based on pencils. Download...
Based on ink splotchings. Download...
Useful for making mosaics. Paint on a layer mask. Download...
Useful for making paper burn effects. Download...