Magic dust effect

Is anyone aware of a method or a tutorial to generate in flash a “magic dust” - “stardust” effect.
I’d like to use it to change one object progressively to an other one but I really don’t know where to start.
Does someone know tutorials examples about this?

Thank you very much.

now whether levitated’s method can be used as a mask to reveal an image, would be based on the amount of particles dispersed over the given area of the image.

If I understand your question correctly, I would use a program from wondertouch called Particle Illusions or Adobe After Effects, which would give very specific control over the “dust effect” and allow you to use it as a mask. Only draw back is file size can get a little heavy if not properly optimized.