Interesting points brought up in this thread.  

As far as alternative currencies in the USA, in may of this year the state of Utah passed a bill in their legislature allowing gold and silver to be used as currency.  Utah also abolished state capital gains taxes on sales of gold and silver, though the Federal tax still applies.  This is an interesting development, the question is whether Utah will be marginalized or become the trendsetter for the rest of the nation.  Greshem's law does apply, and few people will end up paying their taxes with gold and silver, but this does open up interesting options.

What I find interesting is that Bitcoin and Gold/Silver based money are both beginning to come online at the same time as hedges against the dollar.  I believe that a mix of both is a good way to survive inflation of fiat currency.  It is a classic mix of the old and the new.  Of course governments could and may ban the possession of both, as they banned Gold in 1933.  

A p2p decentralized system appears to be the only way for bitcoin to survive a crackdown on current exchanges.  Mainstream media is specifically mentioning Mt. Gox.  This could get ugly.  We live in interesting times.

Skysurfer808