No, that actually depreciates the dollar. The dollar is propped up by faith and an extremely large and diverse American economy. And the fact that everyone else seems to be screwed up even worse than we are at present.
Greece doesn't have the capability of stockpiling a bunch of gold or something. So they're going to have to base their currency off of others. They wouldn't be able to float it, as it would be completely worthless internationally.
China is buying up a lot of precious metals. They might start backing the yuan with something other than dollars eventually.