They're more for backgrounds and banners and shiny things than comicing (they work for covers), but some people may find them useful. Also, does this belong here or in the "tips and tricks" section, because a lot of the software related things seem to come from there?

From oldest to most recent.

http://gigatwo.deviantart.com/art/distoirted-checkers-30055738
http://gigatwo.deviantart.com/art/Gradient-grunge-brushes-30099513
http://gigatwo.deviantart.com/art/Gigatwo-s-Grungestract-brushes-29406809
http://gigatwo.deviantart.com/art/Gradientgrunge2-30798978
http://gigatwo.deviantart.com/art/Gigavector-Bruses-40666155
http://gigatwo.deviantart.com/art/3d-swirl-brush-pack-73311233

Unfortunately, while the GIMP does support the use of .abr files, it cannot save them, so I can't make a PS brush pack.