http://www.curvy3d.com/download.html

Aartform Curvy 3D is an innovative sculpting package for Windows, ideal for first time 3D artists.
Drawing is Fast: Curvy brings new speed to 3D modelling by letting you draw shapes straight into 3D. Create whole models with just a few strokes. Sculpting 3D models for art and games is quick and hassle free.
Painting is Easy: Colours and shapes are easy to work with using Curvy's artist friendly tools. You can sketch and paint colours, forms and bumps directly onto your 3D models, and then export models and textures for use in other 3D software.

Features
 Draw forms straight to 3D. screenshot

 Sculpt details by painting on the model. screenshot

 Paint colour and bump textures onto your sculpture.screenshot

 Pose models using groups.screenshot

 Create materials from painted lightmaps.screenshot

 Export textures to edit in your own paint software.

 Export models to 3DS to animate and render in other software.


Demo
You can download an interactive demo to try out Curvy here: 

Download Curvy Demo 640 KB

System Requirements
Curvy needs a good graphics card to run.
NB: Try out the demo to test your graphics card.