Really bad ideas
In electronics there are also all kind of connectors (like the one from the TV to the, uh VCR? ok, DVD!) which were referred to as "male" and "female" connectors, for obvious reasons**. Anytime I was around someone I hadn't worked with before, the first mention of these would be followed with an awkward pause while everyone in the room had my (female) anatomy flash through their minds. Or it would be followed by some ribald jokes (sometimes these would continue even around people I had worked with for a long time). This is a good example of the kind of "uncomfortable climate" or culture that makes me think twice about being a scientist--do I really belong? Do I want to put up with this for the next 40 years? All these kinds of events that magnify our Otherness can have this kind of very subtle impact. But because each individual event is so small, it seems kind of silly to point to them individually. It's well known, however, that these things really do add up over time and also in quantity.
*Incidentally (and luckily), I never had trouble with the color code because it's simply black-brow-the_spectrum-grey-white-silver-gold. The spectrum was one of those things that seemed to come naturally to me, and even as a very small child I was pretty neurotic about needing my colored pencils to be in rainbow order! in their case. Ahem. And with the resistors, the package around the spectrum was just a fade out from black to white. I never had trouble remembering left from right either--it's funny how people just get that as a toddler or they never do (their entire lives!).
**I have to confess that some of the "male" connectors had such large and deep "foreskins" that I would occasionally get a bit confused!