The asset expansion has produced a sharp rise in bank reserves, and hence the monetary base, which is composed of bank reserves and currency outside the banking system.

FORBES: Why Inflation Worries Are Overblown

This conundrum may also be viewed in terms of the significance of the behavior of the monetary base, which is a combination of bank reserve deposits at the Fed (both required and excess) and currency outside the banking system.

FORBES: The Surge in the Money Supply: Meaningful or Meaningless?

Of course Iceland has been in the news recently because of the meltdown of its banking system and its currency.

CNN: Can Iceland's geo-thermal power re-heat its economy?

Greece leaving the eurozone and adopting its own currency would be associated with default in its government debt, a collapse of the Greek banking system, and would probably tip the Greek economy into depression.

FORBES: 'Inevitable' Greek Restructuring Would Cost Euro Banks $70B

It is still early days but as bitcoin bypasses traditional banking and financial institutions, it is a currency off the grid just as System D.

FORBES: Could Bitcoin Become the Currency of System D?

For starters, Canada has avoided many of the problems that currently bedevil the U.S.--mountains of public debt, a banking system in crisis, the housing debacle and a weakened currency.

FORBES: Magazine Article

Those reserves bloat the monetary base (reserves plus currency outside the banking system), but they have not been used for money-creating bank lending and investing.

FORBES: Monetary Policy, Deflation And Quantitative Easing

It would be unwise for China to float the yuan until it has cleaned up its banking system, but it could repeg against the dollar at a higher rate and shift to a currency basket, which is what the government has said it would like to do.

ECONOMIST: China's economy