3 Types of Texturing
-UV controlled, normal 2d maps
-Projection mapping in 2d space, uses a 3D node
-3D textures
The above images are part of a 3D texture tutorial, and show how useful it can be as it doesnt rely on on a set of UV maps.
To create 3D textures
Hypershade - Create - 3D textures - Select Texture e.g. snow, volume noise.
These textures can be linked up in the hypershade to an objects default texture (e.g. lambert), example connections would be colour and bump.
Once connected these 3D textures can be manipulated in the atribute editor, in the tutorial we used snow as the icing with a volume noise plugged into the threshold, then duplicated it into the bump depth input. By playing around with the atributes we were able to manipulate the 3D textures into looking like a doughnut.