See this post on Cyril Crassin’s blog (I just saw it linked on Tim Farrar’s blog and had to mention it here since it is wicked awesome and I wouldn’t want anyone to miss it).

Cyril is the primary inventor of the Gigavoxels technique which has been the subject of several recent publications.  The Mandelbulb is similar to the Mandelbrot set, but in 3D.  Cyril evaluates the Mandelbulb on the fly to fill the brick cache used by the Gigavoxels.

Mandelbulb + Gigavoxels = real-time Mandelbulb visualization = pure win.