Curiously simple video this - play tones through a speaker and watch patterns emerge in sand / salt.  But the patterns are very curious.

http://www.viralvideochart.com/myspace/really_cool_experiment_in_resonance_and_fractal_geometry?id=1450920883

those are not fractals. get a physics book and look up "standing waves" and "diffraction patterns"

cool effect anyway. i might suggest he try some (slow) music and create a visual animation in tune with the music. (slow so the sand can continuously adapt)

then add color (how?) or use fine semi-transparent very clean sand (or salt), shine a light thru from behind it and view with a polariscope.

what the hey - its EZr to just use fractint <g>