I wonder if they get this by doing an analysis of the text. There are a couple ways of doing this, one involves looking at grammatical and syntax features (a la Gender Genie) and the other is more qualitative, looking at certain subject keywords and emotional keywords as well as comment length. It wouldn't surprise me if comments on this site, analyzed using either method, tended to be more free of gender tells than the writing of the general population. That being said, it's difficult to get more than 65% accuracy no matter how you do it.
Like my girlfriends and me, we feel so betrayed that Sun bought MySQL. My best friend Sarah said that she felt like she had a real relational database situation, commits and all. Sometimes I just want to cuddle with my PHP manual, especially when I have a headache from looking at my screen so long. Maybe after I finish refactoring this program, I settle down with a nice cup of green tea, then go shopping for a USB cable and some new shoes. After a long bubble bath, I'll get back to the rest of my code.
Uh, The boys and I think your algorithm needs a little tweaking.