Something interesting about the Dinka tribe (Sudan):
http://en.wikipedia.org/wiki/Dinka
They have a very specific tradition : when a girl becomes old enough to get married, she wears some pearl rows (and it's the only thing she can wear !), the color of the beads indicating the dowry expectations of the girl's father, expressed in cattle count (I don't know the exact code, but it's something like : a cow for each blue row, a goat for each red row, a chicken for each yellow row... you see what I mean. A kind of human-sized resistor...)
Dinka men also wear similar pearls, but made into corsets (since in the Dinka tradition, a man has to be lean, while a woman has greater value if the is fat...), but for them the code indicates their age. Men in their twenties wear red pearls, men in their thirties wear yellow pearls, and so on.