Why was the SDR created and what is it used for today?
The Special Drawing Right (SDR) was created by the IMF in 1969 to support the Bretton Woods fixed exchange rate system. A country participating in this system needed official reserves—government or central bank holdings of gold and widely accepted foreign currencies—that could be used to purchase the domestic currency in world foreign exchange markets, as required to maintain its exchange rate. But the international supply of two key reserve assets— gold and the U.S. dollar—proved inadequate for supporting the expansion of world trade and financial development that was taking place. Therefore, the international community decided to create a new international reserve asset under the auspices of the IMF.
Today, the SDR has only limited use as a reserve asset, and its main function is to serve as the unit of account of the IMF and some other international organizations. The SDR is neither a currency, nor a claim on the IMF. Rather, it is a potential claim on the freely usable currencies of IMF members. Holders of SDRs can obtain these currencies in exchange for their SDRs in two ways: first, through the arrangement of voluntary exchanges between members; and second, by the IMF designating members with strong external positions to purchase SDRs from members with weak external positions.
http://www.imf.org/external/np/exr/facts/sdr.htmhttp://en.wikipedia.org/wiki/Special_Drawing_Rights