Gender Genie
Heee, this is fun. The Gender Genie is this site on bookblog.net where you copy and paste an excerpt of writing (it works best with 500+ words) and it will guess which gender the author is. I of course skipped over testing it with other writers and went straight to the rather egotistical practice of testing it on myself. It got me right about half the time. It seems very scientific, but of course it can't account for what a big dyke I am, so I guess the answers got a little skewed.
If anyone is reading this (unlikely, this blog is pretty boring) try it out and tell me what your results were.