I can see how gold/silver can work if you need to move from a country in distress to a safe country. Currency of a country in economic disaster will be worthless, but gold will be valueable to exchange in a country where the economic system will be working.
Go get yourself a Kewpie doll. Fleeing a country that's in the middle of an economic collapse is the biggest valid reason to switch from fiat money to gold or other intrinsically valuable materials. There are no more backed currencies. Everything is fiat money nowadays. But, a Kg of gold or platinum is enough to tide you over for a couple of months while setting up in a new country.
There was another thread on trade goods that also touched on this.
http://forums.equipped.org/ubbthreads.php?ubb=showflat&Number=280408&page=1