Artrage
Description:ArtRage is a painting package designed to provide a realistic and fun simulation of using paint on a canvas, along with pens, pencils, crayons, and other tools. You can run ArtRage on a normal Windows machine with a mouse, but it works particularly well if you have a graphics tablet. Even better, running ArtRage on a TabletPC takes advantage of the unique interaction of pen and screen to produce a realistic painting feel.
This is one of the coolest programs that I have seen, photoshop is nothing in my opinion compared to this tool, so check it out at this link.
I drew my foot and it actually exactly like it!