What of the US Dollar?

I don't really know what I'd do if the US dollar died. I have some kind of barter plan happening (I can trade 5 pine nuts for one almond) but obviously there's only so much one can do when the monetary system changes. People wouldn't be able to conduct business as usual if the US dollar goes bust.

For instance, if California goes bankrupt, will there be a functioning state government? What will it all really mean? How will it affect Californians to live in a bankrupted state? Would it mean the local courts would shut down? Would the prisons close and let go of prisoners? Would it mean Mexicans would cross the border and take over cities? Would it mean food would be cut off? Would it mean PG&E would shut down and AT&T wouldn't be available? If the dollar collapses; if California collapses, what will this all really mean?

I know the quality of American men is really low these days. I can't imagine the average American male doing much about Mexicans taking over our cities. I don't think the U.S. stands much of a chance, especially when so many people from other countries are here already who could care less about maintaining the status quo.