Real Pencil Brushes for GIMP

Inspired by DeviantArt user ~wflu and a gimptalk tutorial Grumpy Farmer by *Griatch-art, I felt the need to develop a sketching brush that would feel and look like a real pencil, and that would enable me to draw individual lines. Like that I can skip a sketching stage on real paper.
Have fun, and show me one of your accomplishments!