I seem to recall a plugin or macro that would let you drag out a diagram similar to what is in Micheal's example but I can't find it in my files & don't remember where I got it :( Could also have been part of 'another' editing program as well that I don't happen to have installed at the moment.
The 'divine proportion' fascinates me.
Check this out:
http://en.wikipedia.org/wiki/Golden_ratio