I've just finished reading Steven Strogatz's new volume, "The Joy of X," and will do some sort of brief writeup on it soon. But to hold you over in the meantime, his latest entry at the NY Times, on the golden ratio (what it is and isn't), is here:
"Unfortunately, in the more than two millenniums since Euclid, the golden ratio has suffered from so much hype, numerology and wishful thinking that it’s become hard to separate the myth from the math. Many of its supposed occurrences in nature, anatomy, art and architecture don’t stand up to careful scrutiny. For example, you can find lots of books and Web sites claiming that the shell of the chambered nautilus obeys the golden ratio, but in reality, nautilus shells have average growth ratios between 1.24 and 1.43, quite far from 1.618.
"So be skeptical the next time you see the golden ratio being used to sell blue jeans, stock tips or the perfect smile."