Money can only emerge in an economy if it is first a directly serviceable good. If something provides no direct service to anyone (meaning it does not provide a direct means to anyone's desired ends, and is therefore not valued by anyone), why would anyone buy it?
Because they think someone else will in turn exchange it for something valuable. This is based on speculation just like with all other kinds of money and it is really the essence of money. The use value of all gold in the world is much less then it's current exchange value - the difference is what makes gold money. Bitcoin does not have use value at all and this is what makes it 'pure money'.
How money emerged naturally is not that important, believing that it can do it only in one way is like people believed that only nature can produce organic matter (
http://en.wikipedia.org/wiki/Vitalism) until Friedrich Wöhler synthesised urea.
It's obvious to me that you do not have an adequate understanding of how money emerges.
This book, especially Chapters 1-3, will be a good start:
http://mises.org/rothbard/mes.aspIf you really want dig deeper, you can read this book:
http://mises.org/resources.aspx?Id=3250&html=1When I say that the origin to money is not that important you lecture me with 'you do not have an adequate understanding of how money emerges'? It's obvious that you are not paying attention to the arguments and only discuss with the straw man in your own head.