h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Well, obviously, "etiquette" is a very cultural thing, and may vary from continent to continent.

If you ever ventured in a men's public toilet in Mainland China (not the ones you find in 5 stars hotel lobbies, the real ones, like in the streets of a small suburban village around Beijing), you might thing that European habbits are a bit on the lonely side...

There is a large number of variants, but mostly you'll find a wall wet by many generations of men releasing their bladders on it, and as you stand there, facing the wall, the squatting area would be somewhere in your back, a large concrete area overlooking a gutter slightly larger that the one at the bottom of your wall.
The lack of partitions/separations/baffles make the place a very... social one. Squatters share ciragettes, their manly attributes dangling in the wind, chatting happily, waiting for things to happen "down there", while standers can join the conversation that goes on in their backs.

From what I have heard from my fellow travelers, the women side respects a little more the need for individual space, as only the occupants of (doorless) stalls facing each other have the possibility to share a moment of face to face social chatting.