This was over on the Clydes forum. It's an article about bike fit, and it's interesting. Make sure and click on the "test results" over on the side. The focus is on small riders, but it's a good read for everyone.

The article states that although men and women do need different proportions in bikes, it's NOT due to women having longer legs. He states that all humans, male and female, average the same inseam.

http://www.myra-simon.com/bike/petitest.html