[vubuntu]

> but im talking long term, when currencies will be backed by actual work that provides social and economical value

If it were possible, the absolute currency would be 'life time' as in the movie http://en.wikipedia.org/wiki/In_Time. In the absence of that, something equally dear for staying alive in a increasingly moving towards apocalypse world, like may be bottles of oxygen or water ? But even then, the things that are of value may not be easier/handy to barter/trade with. That is when an alternative 'scarce' 'hard to create and requires resource intensive mining' but 'easy to handle' , 'easy to determine purity' type of resource takes the place as a currency. Gold has that property inherently. Not saying that it is the only absolute resource that has it. But it is a time tested resource with those qualities.