Graphics software

Artweaver
Free painting program.
Best brushes.
GIMP (GNU Image Manipulation Program)
Attempting to make graphic design accessible to a software developer.
To install .scm scripts go to the %USERPROFILE% .gimp-#.# folder and place it in the scripts folder.
Plugin
Fake HDR Look

Great way to enhance a photograph. Script-Fu -> Enhance -> Fake HDR look

Film Grain

Produces an effect that is almost paper like. If the layer hasn't appeared yet, try turning its visibility off and then on. Script-Fu -> Film Grain

Layer Effects

Easiest way I've seen to manipulate font layers. Script-Fu -> Layer Effects