Ooh, something I know a bit about, yay!
I'm now in the most diverse office I've ever been in. We have two managers in the office, one is Mexican (married to a Greek), one is English-Norwegian. We have 21 others in the office, including 7 English, 1 Czech, 1 Swedish, 1 Polish (married to a South African), 1 English-South African I think, 2 Spanish, 1 Italian, 1 Russian, 1 Finnish, 1 French, 1 Egyptian-Finnish, 1 Ukrainian, 1 Turkish and 1 Greek. If you include specialists, we can add German to the mix.
The World Cup was boding to be quite interesting in our office, but sadly the banter never really took off. I was looking forward to that!
I think the greatest potential for misunderstanding comes in written communications. I know the Czech guy can seem abrupt almost to the point of rudeness, but that's now how it's intended, I don't think. For people whose first language isn't English, in their striving for clarity of meaning, they sometimes end up quite abrupt, rather than softer language. I know my Mexican boss (and her boss, who's English), pointed out that with Italians, you have to be quite clear about "I want you to do this, by ____ and let me have ____ when you're done" - don't phrase it as "Could you do this when you get a minute?" Also, they don't tend to read emails.
We also work quite closely with our colleagues in Bangalore and the USA, so again you have to tailor your approach to them - Bangalorians are very polite and helpful, and we try to be like that with them (though sometimes they do misdirect queries to us and we have to be firm in stressing they aren't for us). Relations between my immediate colleagues and some of the American staff (mainly one project manager and a developer) have sometimes been incredibly frustrating, because of time zone problems, and just strong personalities, trying to explain why they're right. Diplomacy and making sure you consider the other person's feelings, are key.
I'll have a think and get back to you with more