For those that didnt know Yahoo Web Analytics provides deomgraphic data on visitors that have been identified within the Yahoo! product sets. (Yahoo!, Flickr, Yahoo mail, etc).
This is a great article on where it comes from an while it might not be 100% accurate (after all what data set is..) it is extremely useful for trending web analytics data.
http://visualrevenue.com/blog/2010/04/d ... idity.html