After reading this thread (http://www.sciforums.com/showthread.php?t=40929&page=1&pp=20), I wonder if perhaps the fractals in Jackson Pollocks paintings could actually have been caused by aliens.

Here for who Pollock was
http://www.ibiblio.org/wm/paint/auth/pollock/
Here for what fractals are
http://math.rice.edu/~lanius/frac/
Here for Pollock+fractals
http://www.maa.org/mathland/mathtrek_9_20_99.html