Recently, I've seen a news feed from a Blender site describing a new free-to-test alpha version Sculpting application. Doodling with it last night, it looks promising and very functional. The realtime view of the mesh tesselation is so great and so far the speed of the application is one of the best yet (aside from the fact that Blender's new sculpting tools work great as well).
By the way, the application is called Sculptris by Tomas Petterson.
Check out the official website here > http://www.drpetter.se/project_sculpt.html