Alien cultures toolkit

OK, maybe this has been done before, but if so I missed it.

This thread is intended to every Narrator who has at some time his players interact with a not well known or custom alien species.
Sometime the players will have to eat local food, play an alien game, or use an alien vehicle, and the Narrator may want, as a way to add color, to differentiate a bit these pieces of culture from what we know (so as to avoid having ground vehicles always looking like a Earth car or a land speeder, for instance).

So we could all share here strange alien elements we designed, like an original design for a car, an usual delicacy, and so on.

What do you think of it ?
I'll post some ideas later (have some work right now).

Ok, here's some cultural traditions from my game:

the Tan-dau are a race of humanoids who think it is unforgiveably vulgar to come in physical contact with anyone else, so while in public they never remove their armor. Except a few years ago there was a fameous romance between a Tandau and a human, in which the Tandau, in true TOS tradition, wanted to know what they were missing. Now together these two lovers have brought a new cultural movement home to Tandau. The "openness" movement is convincing young Tandau to leave the confines of their metal armor prisons. They've made so much progress that moderate Tandau now think it socially acceptable to remove one's helmet occasionally. The social conservatives think this is stupid, as "the helmet is the most important part!"

The Daroxin are a modern Federation race who are not seen far beyond Outback sector because of a peculiar biological trait. The Daroxin are dependant on the biosphere particular to their homeworld, and while they can leave they must return every year or go incurably insane. This has led to the tradition of the "homecoming party", in which all Daroxin who work off-planet return on a particular Homecoming week, which is a planet-wide festival of welcome.

Another cultural tradition of the Daroxin is the tradion of the "signature device". All mature Daroxin have a single small personal item - a walking stick, a magnifying glass, a tricorder, a pocket watch, etc - which they extensively personalize. While some merely decorate or embellish stories about their signature device, all technically skilled Daroxin will have added minature communicators, personalized security, or any other modifications they can think up.