Just wanted to pass along two really useful discussions I saw recently on this topic:
Randall Munroe (of the xkcd webcomic) on Google Plus's gender fields:
https://plus.google.com/111588569124648292310/posts/SeBqgN9Zoiu
Google+ forces you to have a public gender in your profile (although it can be 'Other'). I know they have reasons for this, but I don't think they're good enough.
Luke Wroblewski on Backcheck.com's use of a pronoun field instead of a gender field:
http://bagcheck.com/blog/01-the-gender-question
So after a nudge from Livia Labate, information architect (and all around awesome person), we decided to rethink the gender question on Bagcheck and make it clear why we were asking it and what we’d be doing with the information. Here’s our current approach:
Preferred Possessive Pronoun:
[ ] Her [ ] His [ ] Their
If you're unfamiliar with the Great Drupal.org Profile Gender Field Discussion (hint: it was neither great nor satisfactorily concluded) you can relive it here: http://drupal.org/node/752452

Comments
I gave the Google+ folks a poke about this
If you want to see them change this select box to something more open (like a textfield!) or just pronouns, then send Bradley Horowitz a note about it.
https://plus.google.com/113116318008017777871/posts
Google+ discuss on the topic of formalizing gender in the UI
https://plus.google.com/111588569124648292310/posts/SeBqgN9Zoiu