Makehuman is a free tool for 3d character modeling. I kind a don't like it and the rough features it creates but in more skillful hands it can be a very useful tool. http://www.dedalo-3d.com/
When once I just randomly searched sourceforge for anything related to games I ran onto Art of Illusion. It is a free open-source project written in Java. It has very easy to understand interface and some really nice tutorials. It is unbelievable how fast someone can start work with it in contrast with almost all the other tools for 3d modeling. I recommend it to anyone even just for fun. http://www.artofillusion.org/