Anthropologist David Graeber recently sent in his essay on the 5000 year history of debt (orignally published in Mute and Eurozine). Aside from being an interesting read in general, this effort (which he is just now finishing as a book) is an interesting resource for the Eternal Coin and the Long Finance project.

Debt: The first five thousand years by David Graeber

Throughout its 5000 year history, debt has always involved institutions – whether Mesopotamian sacred kingship, Mosaic jubilees, Sharia or Canon Law – that place controls on debt’s potentially catastrophic social consequences. It is only in the current era, writes anthropologist David Graeber, that we have begun to see the creation of the first effective planetary administrative system largely in order to protect the interests of creditors.
http://blog.longnow.org/2010/04/22/debt-the-first-five-thousand-years/