Read it at Reviving Economics
I don't understand how some liberal (read: New Keynesian) economists like Stiglitz want to, essentially, create the same conditions that Greece now faces - only on a global scale.
Global Currency Reserve
by Garth Brazelton
Mentions Warren Mosler at the end: "And I happen to think Warren Mosler's idea from a year ago of essentially (and somewhat sneakily) creating a new Greek currency (but not quite) by turning Greek bonds into a form of money (means of payments for public debt - pay your taxes with a bond!) was pure genius."
See also the Wikipedia article on the Bancor global currency proposed by Keynes for some history on the concept.