Sculptris

Sculptris is another program that is free to use released by Pixologic, the same company that made ZBrush. A very nice program to use, although its nowhere near the power or the vast array of features as its big brother, it can do sculpting very easily. Much easier to use then ZBrush, and has about 20 buttons, in the right hands you could easily make anything that is as good as in ZBrush. Hear are a couple of models i've done in Sculptris and rendered in Maya