I did some traveling with the military years ago, here's a few things I found:
Spain - lived there for 4 years. In a restaraunt, in America it is polite for a man to keep one hand in his lap. In Spain, they wonder what the hell you are doing with your hand in you lap. Everyone keeps both hands on the table. Also, they put some STRANGE stuff on Pizza: Fried eggs, baby octopusses, etc.
Drinking: If I'm not mistaken, drinking age starts at about 16. There are discos everywhere, it is like they were back in the 70's. Saturday Night Fever was a big movie over there (this was 1987 to 1991). There were what we called "teeney bars" where the kids would learn to drink and dance, when they got a little older, they would graduate to the real bars/discos.
Open air markets: Kind of disgusting if you're not used to it. They generally didn't have big refridgerators like we have in the states, and did their food shopping every day. There were these open air markets with all the mets and vegetables, the smell took some getting used to. They sold skinned rabbits, but they had to leave the heads on them because apparently there were people selling cats as rabbits. With the head on, no one could get fooled.
TV: They showed strippers on talk shows, game shows, all kinds of shows. Saturday morning TV, you'd end up seeing some girl taking off her clothes. They would have a talk show and it would be like a show here in the states, then in the last few minutes they would bring a girl out, play some music, and she would take off her clothes.
Bars: If you were in a bar that you liked, you threw your trash on the floor. When you were looking for a good bar, all you had to do was find the one with the most trash on the floor.
Drinking: LOTS of alcoholics there. The drinks were very strong compared to here int he USA, a Rum and Coke was about 75% rum, the coke was barely noticable. When I cam back to the states I ordered a rum and coke at a bolwing alley, I thought they had made a mistake and just gave me a coke, I couldn't even taste the little bit of rum in it. Also here in the states when you go to a bar, you put your money on the table and the bartender takes the cost of your drink as you order. In Spain you drink for hours, then when you are leaving they tell you haw much you owe. I never could figure out how they could keep track of everyone.
Australia: Australia ROCKS! If you ever get the chance, go to Australia, the best people in the WORLD. Can't think of anything "weird" about Australia, everything seemed a lot more expensive, and they ate some things you wouldn't find here (vegemite - enough said), but the people there are for the most part great. I was in the middle of the outback (Woomera Air Station) so I didn't get to see a lot of the culture except on the rare trips to Adelaide. Oh yeah, there is no tipping in Australia. Taxi cabs, meals, etc., you don't tip for these things.