Autodesk Inc. has 123D Sculpt (iTunes Link) in the iTunes App Store for FREE for a limited time.

The most fun you can have sculpting without getting your hands dirty!

With Autodesk 123D Sculpt you can sculpt and paint interesting and realistic 3D shapes.

It’s easy to get started. Choose a shape from the library of creatures, humans, vehicles, and more. Then push, pull and paint to make the sculpture your own. When you are done, take snapshots in the camera room or create animated QuickTime turntable movies to upload to YouTube or email to friends.