If you actually care about fiddling with SDR, this will grab SDR values from IMF website and put them in a useable form, XML or yaml. (requires python and pyyaml).

http://kphretiq.com/Scripts/Xrate.tar.gz

http://en.wikipedia.org/wiki/Special_Drawing_Rights

I guess now all we need is a titanic pool of data to push the IMF to calculate it. How many bitcoins to buy an island? :-)