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 a sky focused sunset set, intended for the more experianced user who has both a good idea what they are looking at and what they are looking for. The scenes have been optomised for render speed and as such only provide as little as is needed to create the effect shown. This video http://www.youtube.com/watch?v=yxozLNmp12w&feature=related
offers some pointers for dealing with volumetric clouds.