Knowledge of multi-cultural business and social etiquette is increasing in necessity. Living in such an electronically connected time, when even telephone access to the farthest reaches of the world are reasonable (or free with Skype! gotta love Skype...). Even I hardly go a day without speaking to or corresponding with someone from another hemisphere (and that doesn't include blogging).
Pam authors Escape from Cubicle Nation and she has a terrific post with insights about consideration of non-US cultures. After enjoying her post, be sure to read her post comments. They are laced with even more ideas and points--definitely worthy of reading.
After that, you might enjoy my prior posting: Doing Business Abroad: Need to Know Etiquette. The post is over a year old and still gets very high readership. In it, I link you to resources for tips by country.
Special hat tip to Rob Millard who's post about Pam's led me to catch up on her blog in my aggregator!