What does "talk to the hand" mean?

I saw the phrase "talk to the hand" on many funny stickers which seems like expressing the idea that you want to stop the topic or conversation which you feel uncomfortable or not interested in.

But I'm curious about what do English native speakers think about this saying? Is this offensive or impolite? Could the phrase be used with person I'm not very familiar with?

Talk to the hand ['cos the face ain't listening] stems from black English in the 1990s, often borrowed by the younger white generation as many urban sayings are.

To answer the question directly, it is offensive and impolite in any circumstances, albeit mildly so.

More information of interest here http://www.bbc.co.uk/worldservice/learningenglish/radio/specials/1453_uptodate3/page19.shtml

It means that the person saying it is not listening so you may as well talk to their hand.

It's often extended to something like "Talk to the hand, 'cause the face ain't listening".

I believe an image will help here:

There is a wikipedia article on talk to the hand:

"Talk to the hand" (or "tell it to the hand") is an English language slang phrase associated with the 1990s. It originated as a contemptuous way of saying one does not want to hear what the person who is speaking is saying.

A well known example would be this scene from Terminator 3.