On a project I have recently finished, (well mostly now after crits!) Someone asked for the particle system settings i used. Being several particle systems together i felt it would be easier if i created a blend of it. The .blend will need the speed and dampening settings adjusted to your particular scene, and there is a brief description of what is on what layer in the text editor. Don’t forget you can add even more particle systems to blend together, using texture images packed in project perhaps to bring out more definition.
wmv rendered from .blend (152kb 800*433)
the .blend (282kb)
and shameless plug of project
Hope this is a help to someone!