The intuitive, artist-friendly sculpting toolset that defined the initial release of Mudbox is further enhanced in Mudbox 2009 to easily handle extremely high polygon counts; meshes can be subdivided to tens of millions of high-quality polygons across their entirety, with virtually no delay and no loss of resolution when tumbling or when moving to another part of the mesh.
LINK:
http://www.3dtotal.com/team/Tutorials_3/video_mudbox2009/sculpting01.asp