Digital Media Minute has done posts before on tools for making 3-D art including a slick 3D character creator, but take a look at Sculptris, a really impressive, free digital sculpting tool or 3-D modeler that you can use to make incredibly detailed and organic-looking 3-D figures. If you have ever wondered how the incredible figures that you see in video games and other places are created, take a look at this piece of software. I think that a fairly untapped market is to sell to people who might be interested in 3-D sculpture just for the sake of making cool models in 3-D without any further application necessarily. For Mac, Windows, Linux.