Oooo...my kinda topic. Raaid's example tends to stability, i.e. regardless of the input the final output is eeee. But it does skirt an interesting topic, check out the links AndyJWest supplied above, maybe some 3D fractal videos as well if you'd like to visualise 'chaos'. And if you're a computer boffin then you'll probably like Holland's work on Genetic Algorithms and Cellular Automata.
The question of whether there is 'order in chaos' has kept me busy for many years.
