Well "Voodoo dolls" as they are most usually thought of, sticking in pins to bring pain and misfortune to another, do not exist. They are merely Hollywood myth.
The idea for them probably comes from the "minkisi", nail fetishes from the area of the Congo. If your friend is looking for a true ethnographic artifact this might be it. If he is looking for some pin-sticking Hollywood stereotype he is out of luck.
http://images.google.com/imgres?imgu...%3Den%26sa%3DN