$6.6 billion in cash was "lost"[0] and then found[1] in Iraq which I can now visualize as 66 pallets of cold hard cash. How do you lose that?
[0]http://www.cnn.com/video/#/video/bestoftv/2011/06/13/exp.tsr... [1]http://security.blogs.cnn.com/2011/10/26/once-thought-lost-a...
[Edit] There is $1.18 Trillion in circulation in the USA, about as much as in the last image: http://www.federalreserve.gov/faqs/currency_12773.htm