From Harvard Natural Sciences Lecture Demonstrations this experiment caught my eye as it illustrates emergent properties really well. Patterns that are not found in the single entity but arise from the variance in it’s mutlitude. The effects of an emerging property correlates rather then being in direct causal realation to its parts.
In philosophy, systems theory, science, and art, emergence is a phenomenon whereby larger entities arise through interactions among smaller or simpler entities such that the larger entities exhibit properties the smaller/simpler entities do not exhibit.
Definition from Wikipedia – Emergence