eBay announced Monday that it would ban all commerce in ivory, including most heirlooms, to avoid providing a market that will encourage the slaughter of endangered elephants. The eBay ban on Ivory will take effect on January 1, 2009. At the time of this writing there are about 38,000 ivory items for sale on eBay. Of course, these are not all items made from ivory, most are the color ivory. I’m not sure how eBay is going to enforce this ban, as the word ivory is so common in its listings. I can’t even figure out how to narrow the…