One thing that used to really get my goat when I worked in the US was the frequent and (in my mind) overly-enthusiastic use of email. I must add that I had two different experiences working in two different jobs. In one job, email discussion was an extension of face-to-face and phone conversations. In the other, it was pretty much email all the way. And this was where the problems (for me) arose.
Much to the horror of some of my colleagues, I was in the habit of switching off my email client so that I could actually get some work done. I'd check periodically for urgent emails that required an immediate response and then log off again. I hate being interrupted in the middle of Very Important Work and besides, isn't this one of the top recommendations of time-management experts? I guess not everyone agreed with that particular piece of wisdom, because my phone would ring and a voice bristling with indignation would ask why I had not responded to x,y or z. After checking my email, I would see that they had sent it only ten minutes earlier (GRRRRR!!!!) and it was something that really could have waited (DOUBLE GRRRR!!!!). Why does everyone think that their issues come first with you?
Anyway, my situation these days is much the opposite. It's mostly face-to-face and phone discussions interspersed with emails, thanks to a string of unreliable ISPs and a still growing email culture in Nigeria's workforce. Just when I want to complain, I think back to the times when my colleague in the cubicle next to mine would send me an email asking if I wanted to go to lunch and then I am grateful that Nigerians are somewhat less into the personal space thing than Americans. However, where's that happy medium when you really need it?