Following Narenj's thread about hand and head movement in Indian films, it happened to me that the subject of body language differences can be a very hot topic to talk about here.
I wonder whether this topic has been talked about here or not?
The differences can be the cause of misunderstandings in face to face interactions.
For example 'thumb up' in English means ok, thanks, ... but in Farsi using it is very very rude, unless you mention you mean the English connotation.
The issue of 'proximity' when one is talking to others is also part of body language in different cultures.
What are some specific body language expressions in your culture? What do they mean?