Hi Michael,

And just to confuse things even that bit more, you've got SensAble's FreeForm & ClayTools.
http://www.sensable.com/products-freeform-systems.htm

One of the Members on 3dcadjewelry Forum has FreeForm & a couple of others have ClayTools & they've done some really great work with it .
Here's one site with some examples.
http://www.harryhamilldesigns.com/Portrait.html

It really seems like the answer for those wanting something like a NURBS type "Organic Sculpturing".
But from what I understand, unfortunately it's very expensive & the system requirements are very specific.

regards Colin