If you wanted to deride the fact that many folks here won't spent multiples of effort on special, experimental, no-right-answers-and-likely-to-be-criticized-for-it-if-you-even-try cases that affect minuscule fractions of their potential user base, well...get in line behind the IE5 advocates, I guess.
Someone recommends using a free form entry for gender. No amount of normalization will fix the "ham sandwich" entries (except that we know they are nearly all male), so you'd trade the integrity of a small percentage of your data for the appearance of "making an effort" for the vanishingly small percentage. Net fail.
Just to be clear, my primary feeling here is that -- in the hypothetical case where gender matters -- you're best served by keeping it simple: (female | male | other/it's complicated | prefer not to answer). This should serve all cases equally.