Check out my new Gimp brushes here: [link]
The archive now has both .gbr and .png files in it. The .png files are for Photoshop users so they can possibly save down the brushes on their own. I don't have the software to create .abr files.
HOW TO INSTALL
Download and unzip. How to install Gimp brushes (just pick a video): [link]
TUTORIAL ON HOW TO CUSTOMIZE GIMP'S INTERFACE: [link]
Best used with this [link]
Gimp version, which I truly recommend. It has everything I used to miss in Gimp, such as smooth pressure sensitivity on brushes and colour blending.
EDIT 8 Dec 2009: The newest Gimp version makes these brushes work just as well without the Gimp Painter features. Gimp has come a long way in a short time!
Most of these brushes are made out of thin air, but I've had uses for them
1. The crescent shaped brush is my favourite. It leaves a hollow line, which can be made to look like a snake in just one stroke, but I haven't painted any snakes yet
I use it for almost everything, but mostly sketching, smudging highlights on hair and it's nice for skin painting as well when used with the blending brush.
2. A normal 50px round brush, with the spacing set to 1 so you don't end up with those ugly, visible circles that the original brushes do. It may lag a bit.
3. I don't use this brush very often. As you can see in the preview, it can do many things. The blob to the top looks somewhat like leaves and could be used for trees/bushes. Below I have made three strokes side by side and it almost looks like some sort of chainmail.
4. Another texture-ish brush. I've used it for cloth before.
5. A lovely soft brush that I use when I want a more delicate round brush.
6. A wispy sort of brush. Quite nice to use as eraser to fade away objects.
7. My favourite sketching brush number one. Much the same like a normal round brush, but with smoother edges.