Ten Bryce 7 Pro source files featuring volumetric clouds. Important note. Most of these scenes would take between half an hour and an hour to render on a P4 3.4ghz powered PC or about 5 minutes on a i7 system. Volumetric clouds are demanding on your system, do not expect instant results!
The pack is sky focused, intended for the more experienced user who has both a good idea what they are looking at and what they are looking for. The scenes have been optimized for render speed and as such only provide as little as is needed to create the effect show.
This video http://www.youtube.com/watch?v=yxozLNmp12w&feature=related offers some pointers for dealing with volumetric clouds.