When a woman enters a bathroom there are many possibilities, each of which has its own unique response:

1. the bathroom has other occupants

pee and wash your hands.

2. the bathroom is empty

pee, and if the coast seems clear, perform other potentially noisy, smelly bodily functions. this is done AS QUIETLY as possible! handwashing when the bathroom is empty is purely optional. unlike men, we ladies don't have to have direct hand-to-genital contact to pee (we have a hand/genital toilet paper buffer zone).

3. someone enters the bathroom while you are going:

you have two options. either:

a. finish as quickly as possible and exit the bathroom while the other woman is still in the stall. even if you are not making poops, you don't want anyone to think you are by staying in the stall for a long time.

b. sit quietly and pretend she is not there (etiquette states that women do NOT acknowledge in ANY way women in other stalls). wait until the other woman is gone and continue on with your business. this is called going into "stealth mode".

4. you hear/smell someone elses noisy, smelly bodily functions:

do NOT acknowledge this in any way! the other womans dignity must be saved. finish your business and leave the bathroom as quickly as possible, AVOID CONTACT WITH THE OFFENDER AT ANY COST! if you make it out of the stall before her SKIP HANDWASHING AND EXIT THE BATHROOM.

as a side note, and a tip to the ladies: whenever possible use the handicapped stall. it is larger, and tends to be father away from the door. less people use it and so it tends to be at least marginally less gross.

um.. am i the only woman who has never considered most of these rules of etiquette? am i a rude person? i go, i flush, i wash, i leave.. is that so wrong? if someone is stinking up the can, i try not to inhale any more often than necessary. if someone comes in while i'm peeing, big freaking deal. what the hell else would i be doing in a bathroom stall? likewise, if i come in while someone else is peeing, i don't do anything special to disguise my awareness of this fact.

it's very odd to think that anyone would be this embarrased about such an often necessary thing. i'd be wholly neurotic if i thought this way, considering how much coffee i drink. to women who have these qualms, i say: sisters, the bathroom is a special room for peeing. no one thinks you're just hanging out in the stall, it's fairly simple to deduce your purpose in being there. moreover, everyone else has been in such a stall many times in her life and it would be entirely ridiculous for anyone to judge you based on the fact that you have to take a tinkle. now stop being silly. and no, i will not run the water while you go.

The most bizarre thing about female bathroom etiquette is that the vast majority of US women seem to have a phobia about having other people hear them pee. Other women will time their urination such that it happens while you are peeing or flushing, to ensure that you are never subjected to the terrible sound of their urine hitting the water. It's very strange.

The thing about not having others hear you pee is even stronger in Japan, where they saw the need for a technical solution: in many japanese public toilets there is a device called Sound Princess (dunno if there are other brands) which will either on the press of a button or automatically, generate an artificial flushing noise. This became necessary because previously, many women used the real flushing noise for the same purpose, flushing throughout the whole business and wasting a lot of water.

Most importantly:
5) Women must NEVER ever open feminine sanitary items within hearing range.
If there are others in the immediate vicinity (eg stall next door, within same bathroom), either wait until the other people are gone, or take one of the following cover-up methods.

1) Cough loudly to cover noise
2) Rattle and scrunch the toilet paper/dispenser
3) Wait until somebody flushes the toilet
4) Hire a band to play outside so that all other noise is irrelevant
5) Turn on your walkman (if you can't hear it, then it's probably ok).
6) *Accidentally* bash the wall or the door with your hand or foot to cover any noise.

As I attend a girl's secondary school, I can verify this information to be accurate. Most cover-up courses of action have been attempted by pupils at my school (apart from the band one, but as a substitute, a stereo in the room next door was turned up really high). The phobia against noise in women's bathrooms is highly amusing and amazingly stupid. Everybody is struggling to be silent, and yet wishing somebody else would make noise.
Go figure.

Some of the "rules" I've found, at least around here:

1. Take the stall by the door, and if that's occupied, take the stall nearest the door. This means that the last stall (the handicapped stall) is usually unoccupied, and the stalls nearest it are cleaner, better supplied, etc. than all the others. As for the "advice" given above, I've rarely encountered wheelchair-using women using a public toilet (no kidding, please, I haven't!), and hence have found the extra room affords an ideal place to deal with extra-excretory activity (looking through my handbag, sneaking a quick toke, major costume changes, etc.) that might need more time and space than the usual. The stalls near it are my first choice, of course, and naturally, my spidey-sense is quick to detect anyone moving near that part of the room.

2. Never acknowlege smells, sounds, or anything else in a stall, but be quick to at least smile and give a word while near the sinks. This is a) to minimize embarrassment, since it's easier to pretend that you're here for something else that way, and b) to exchange intel, small favors, etc. out of range of menfolks and other prying eyes. The resulting low-level noise keeps the attention away from stall-dwellers and onto more intreguing topics such as "Is there lipstick on my teeth?" Middle-aged and above women are more likely to do this than younger, since they're more likely to have other activities to attend to (cosmetology, hair fussing, etc.)

What backwards, paranoid, anal retentive planet do all you people come from?

There are no rules for which stall to take; just pick the first clean one with paper.

Need to pick up a tampon on the way? Go for it. Anyone who's uncomfortable with the existence of tampons is in the wrong restroom.

Speaking of which, if you're at someone else's house, be mindful of what you flush down their toilet.

Were you talking to someone who entered the restroom with you? Keep talking even when you're both sitting on your porcelain thrones, especially if it's a friend or sibling or someone you know well. The exception to this guideline occurs if the person you were talking to is someone like your new boss. You might want to wrap up the conversation before you enter a stall or let them decide whether or not to keep the conversation going and then you can pick it up as soon as you're both face to face, just for the sake of professionalism. If they're done before you or you don't want to talk at that particular moment, tell them you'll catch up with them or to just give you a minute or whatever. Don't you women have girlfriends who you go to the restroom with all the time when you're out at a restaurant or club?

For Pete's sake (and anyone else who may shake your hand at some point in time), Wash Your Hands! I don't care how often you shower or how clean you think you are; there are germs all over that stall and germs don't sit still. Did you touch the door handle? Did someone else who maybe isn't as fastidious? Did you touch the toilet or did your hands get within an inch or so of touching it? Did you touch the area near the little disposal for feminine hygiene products? That's the dirtiest area in the entire restroom.

And one more thing. The lines at women's restrooms are longer because it simply takes longer on average for a woman to use a restroom. There's no big secret to this. If men didn't have urinals and washed their hands, they'd take just as long.