Agh! I wanted to put that in and I even remember downloading it... Just never marked it as an installed hack so I didn't remember to actually install it
I'll get on it
Ok, so now gender options are available in the profile options inside each user's UserCP.
Right now, the gender shows up in a weird spot in the postbit divisions, however, I'll add it's own little boxed section under Age when I have time tomorrow. In the mean time, spread the word that this option exists!