...aside from handcrafting such cosmic clouds in a 2D program...dunno...and for ideas as to what 3D or fractal generating program that might create these motifs/shapes, I suggest you cruise on over to either pandromedia.com...or over to the MojoWorld discussion forum here at Renderosity...or at 3D Commune, and address your question directly to "Doc" Ken Musgrave...as he might be able to point you in the right direction...