Two things.

1) "other" as a gender.  Perhaps even more detail.  

Those of you who have been, plan to be, identify with or play as a different gender from the one that was culturally assigned to you at birth on the basis of your observed anatomy:  I salute you. You are making the best of what must be a very difficult situation.  Good luck, and blessings.

I get it, there's a spectrum.  My own gender identity is not entirely clear cut - I sometimes feel like more of a butch dyke than a straight man, or I'll refer to myself as "straight but queer."  But there are a great many people, many of us quite open-minded, who feel the need to assess the matter of your gender on our own quaint and culturally confining terms.

I'm really sorry, but when you show up in my searches for women, I do click on your profile and laugh at you, and then hide you.  I'm really, really sorry about that.  Sometimes you're almost hot if I squint a little.

I'd like to see OkCupid implement something with more detail.  It doesn't have to be a mandatory item.  Perhaps you could do male/female/other, or "check all the genders you identify with", or how about a slider?  I don't think I'd push that slider all the way to "male," and I might be too feminine for some women.  Particularly those that like sports and pickup trucks.

2) More detail in "looking for"

The problem here is that there are a LOT, and I mean a LOT LOT of women on this site who list themselves bisexual, but are only looking for women.  I leave it to the lesbians to debate as to whether or not you're actually bi or not... it's worth noting that there are virtually NO women who are involved in a woman, but looking for men on the side.  Put that one in your kama sutra looseleaf.  The crux of it is that from my point of view, you're gay.  

The simple solution - or at least it stays simple if we don't combine it with my first suggestion -is to turn "looking for" into a matrix, and maybe add "involved with" to that.  I tried to put in an HTML table to illustrate that, but the journal system doesn't seem to like that.  Let's try this:

      | new friends | LT dating | ST dating | penpals | casual sex | involved with
 Men  |
Women |

(and yes, this means that you'd also have to be able to search on the other person's 'looking for'.  Why can't we include our own gender in that now, anyway?)

When I'm searching, I'm want to know who's potentially interested in me now, not someone who might have been in the past or might be in the future.  I don't know if I'm interested or not in being a tertiary in your Heinleinesque nest (tempt me), but I'd like to at least be able to account for that in searches.  I would assume there are many lesbians who do not want to meet some chick whose husband is trying to hook up a threesome, and just as many gay men who would prefer not to meet up with some married guy.  

Perhaps it's just the people I'm searching for, but OkCupid seems to skew several standard deviations from the norm.  That's part of why I like it.  Gender has become a very fluid thing in our culture, and I'd like to see this site take that into account.

I should probably send this in as a suggestion, but I'd probably just get an opaque 'thank you' note, and I thought it would be more fun to spark a discussion and piss off some trannies.  

Alternately, I'm a programmer, and I could build a site that handles gender and preference this way.  Would anyone reading be likely to join such a site?  Does it already exist?

interesting semi-relevant background read: http://qntm.org/gay