this would just lead to a socialist society and take us back to the dark ages. Currency value at a very broad level is representative of the living standards in a country. For example, dollar against euro or euro against peso etc. Currency is based on the gold standards. Now, if all countries have a common currency, the living standards are assumed same everywhere, which would mean that a country where infrastructure is poor and resources are scarce would still have the same currency value and they can afford the same salaries and amenities compared to a country where infrastructure and resources are developed. This would mean a disincentive for the country to prosper since it can already afford everything. In turn, countries would start hording on gold to increase the number of currency bills they can publish. This in turn would lead to abolition of the gold standard. This in turn would require a new standard and you would go through the same cycle again where someone would suggest this idea again.

Now, the idea is for each country to have organic growth so that they can strive for better standards of living and in turn higher currency value. The whole idea behind currency is economic incentives to prosper and to maintain standards of living based on growth and infrastructure.

Please understand that currency is just a way of maintaining living standards, it really has no political motivation. It's a good thing we have currencies. What you are suggesting might work in a perfect world we absolute honour and no ambition. But that would be a pretty dead world, won't it ?? !!!

If you are familar with the Euro where several countries are already using one common currency, then it's not that hard to believe that the U.S. won't be far behind.

I don't really know what to rate this, because it WILL happen one day, I can almost promise you. When Jesus Christ heads back to earth to take his people back up to Heaven, the Antichrist will be, literally, a " world leader". All nations will be under his devilish rule, so I can imagine he will create a world-wide currency. However, I do not recall the Bible specifically mentioning currency, but it's kind of conclusive,

Too difficult to manage and wide-open to corruption and manipulation. As is, it is difficult for countries to manage their own currencies. Very doubtful this happens during our lifetime.

Yeah right and lets wave a magic wand and solve world poverty too. The complexities involved with just our economy are so great that any attempt to univeralize money would wreck the economies of the US, Japan, and Great Britain simply spreading the third world misery throughout the world.

An idea who's time will come. Imagine a worldwide currency that can be spent anywhere in the world and who's value is determined by each country? It's kinda happening now with US Currency being valued over some other countries' own bills.