http://www-ui.is.s.u-tokyo.ac.jp/~takeo/java/smoothteddy/index.html
You can make round 3D models such as teddy bears quickly, and paint them in an integrated environment.
Smooth Teddy is a small, yet highly amusing program by Takeo Igarashi. A sort of “3D playground”, it allows you to fiddle with 3D models by scribbling shapes that are automatically given volume. Once you have your first amoeba on screen, adding pseudopods is just a matter of painting shapes over it: once a secondary shape is given volume, you can displace it over the first one, clone it if you want, and finally merge the two into a single piece. Modeling in this way becomes an intuitive process, and though it is not very precise nor very quick, the program has a high cuteness factor which will make it appealing to everyone, not just young kids.
Besides sculpting 3D models, Smooth Teddy gives you the option to paint them directly over the mesh, and the finished models can be saved and used within Alice, a well known environment for the creation of 3D interactive content. Takeo Igarashi also mentions a plugin to export models to X3D and VRML formats, but unfortunately the link provided doesn’t work.
All in all, Smooth Teddy is a very nice application that worths trying. If you want to go the professional way, then there´s the powerful Zbrush, but if all you want is a sketch pad for casual amoeba designs, Smooth Teddy has all you need. 🙂