Thanks for bringing up Fibonacci, tsuwm. You sent me into a whole new world of fascinating revelations, eg http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/fib.html about Fibonacci numbers, golden ratios, how rabbits breed, stems divide and spiral seashells are constructed. I marvel at the connection between the seemlingly purely academic analysis of a number series and the beauty of nature.