You just type (or paste) a text (preferably more than 500 words) into the text field and the Gender Genie analyses your writing patterns to determine if you are male or female.
I tend to believe it works (at least somehow) because I get "male" most of the time. Then again I have no idea if it works at all if English isn't your mother tongue.
Well, it's fun anyway: Gender Genie

"Inspired by an article and a test in The New York Times Magazine, the Gender Genie uses a simplified version of an algorithm developed by Moshe Koppel, Bar-Ilan University in Israel, and Shlomo Argamon, Illinois Institute of Technology, to predict the gender of an author. Read more at BookBlog, The New York Times, and The Guardian."

Female Score: 356
Male Score: 315

Guess I'm close to somewhere in the middle

It depends a lot on the kind of text you submit. I was feeding some of my Englsh homeworks to the genie and my nonfiction values are clearly male most of the time while my fiction values are not so clear and sometimes even female.

I entered my introduction which is long... and:

QuoteWords: 1300

(NOTE: The genie works best on texts of more than 500 words.)

Female Score: 1382
Male Score: 713

The Gender Genie thinks the author of this passage is: female!

Interesting! 

tink

I entered this: (I just kinda wrote it as I thought. Kinda short, and it doesn't work so well on short things.)

He walked the road of someone of sure death, but faced it as though he could do nothing else. His eyes were filled with hatred of the whole world, but he knew that nothing else would suit him better.

His life was filled with misery and pain, but he could take anything. He had learned to block out the thoughts and criticisms of other peoples at a young age.

He knew he didn't deserve to die this way, but that wasn't his choice to make. He felt as though nature had played some cruel joke on him, unto which he had no power.

And so, with this in mind, he marched forward to take his sentence from the Grim Reaper, for he had known, deep down, that this was to be his fate. The inevitable truth bore down upon him with his last breath; he could have never been who he wanted to be. He knew something that even the Grim Reaper knew not; he was to be Death itself, killing the innocent, and sparing those who still could go on. "A pitiful fate," he thought, as he took Death's chair, "for one so pure of heart."

-------
I read it over and it sounds so sad. Hmmm... It said 'female', but I don't trust that thing too much. I've tried it before, and it wasn't too accurate. I wonder where it got that chart of words from...?

Words: 841
(NOTE: The genie works best on texts of more than 500 words.)

Female Score: 1535
Male Score: 833

The Gender Genie thinks the author of this passage is: female!

I copy and pasted my post from here in there. I was kind of pleasantly surprised.

Later,
Anna

i entered a bit of my essay.

Words: 611
(NOTE: The genie works best on texts of more than 500 words.)
Female Score: 509
Male Score: 1074
The Gender Genie thinks the author of this passage is: male!

wahey!

I find that 'he' and 'she' are very important words in it's scale. If you use 'he', it is more likely to think you are male, if you write 'she' it is more likely to think you are female.

I submitted two pieces and the results were very similar: 60% female; 40% male

Quote from: The_Unforgiven on January 30, 2008, 04:10:26 PM
I find that 'he' and 'she' are very important words in it's scale. If you use 'he', it is more likely to think you are male, if you write 'she' it is more likely to think you are female.

that's hella unfair. you could be writing about a female character, not about yourself. 
i did it again, this time with a bit of some AFI fan-fiction i wrote last may.   

Words: 4724
(NOTE: The genie works best on texts of more than 500 words.)
Female Score: 5589
Male Score: 5086
The Gender Genie thinks the author of this passage is: female!

oh god damn it
blah, that was last year. 
no, wait, i'll do all of it.

Words: 20717
(NOTE: The genie works best on texts of more than 500 words.)
Female Score: 22328
Male Score: 21010
The Gender Genie thinks the author of this passage is: female!

still, god damn it