One of the best examples of communication through body language I have seen in a while is the lastest Gap commercial where the hot/cute, petite black girl flirts with 3 handsome white guys. No words are said in the entire commercial but the black girl's facial expressions are priceless and clearly communicate her intent.
It would behoove any guy or girl having trouble communicating with members of the opposite sex to watch this commercial over and over and learn from it.