OkTrends
This was the first entry:
http://blog.okcupid.com/index.php/page/21/
In the URL address you can skip from pages 1-21 by just changing the number in red
http://blog.okcupid.com/index.php/page/21/
It's a shame that it was shut down when match bought them a while back.
I reckon a lot of folks here have never read the blog. It's so interesting I usually reread the entire thing every few months.
The blog doesn't make conjectures. It analyzes raw data. It may not be what most would like to hear but its true.