Universal Currency?

Due to the current state of the United States economy, and its effects on the rest of the world more and more countries are suggesting a universal currency. The US is not for this idea, with good reason. The majority of nations depend on international trading. Some argue that a universal currency would cut down or eliminate the transaction costs that come with international trading. Another reason countries want to adopt a universal currency is to give them confidence in the currencies of their trading partners (http://www.gocurrency.com/articles/universal-currency.htm). A universal currency would hedge against the depreciation of national loans from country to country due to fluctuations in exchange rates.
On the other hand, implementing a universal currency would not be beneficial across the board. Adpoting one currency means adopting one monetary policy with universal interest rates. The
The problem with that is no two countries are ever in the same economic position. What would be beneficial to one country would be detrimental to another. Countries that oppose a univeral currency, such as the United States, are also worried about nationalism. Currency is a part of so many countries' cultures. Doing away with them would take away from the individuality of nations. Finally, creating a universal currency would mean creating a universal bank. This means a select few people would be responsible for the flow of money all over the world. This has disaster writtien all over it. How would we go about appointing these peoople? What countries would have the greatest representation? Too many opportunities for corruption would arise. As you can see the cost of universal currency greatly outweighs the benefits.