I think we all already know about the relation between money and gold. In simple words a currency note is equal to some amount of gold. Due to this bindings, banks or government can't print currency notes until they have equivalent gold. But surprisingly, its not true for US Dollars. A long story exist behind this and you can read in Ron Paul's article The End of Dollar Hegemony.
We can conclude that soon US currency will become a piece of paper once the OPEC announce Euro as trade currency for oil, as US had created oil as "artificial" backed for US dollar. The only resistance in Euro as trade currency for oil is present reservoir of OPEC countries, only Saudia having 1.3 Trillion US Dollars. I came to know, all countries of world have started transition from US dollar to Euro and gold.
So, if you are going to start any Startup then make Euro as trade currency, or you can select Gold too ;)
P.S. Thanks to my teacher Mr. Bilal for sharing such valuable information.