The Austrian School economist Steve Horwitz has a great article on fractional reserve banking
here. People who criticize fractional reserve banking should read it.
Truly an enlightening article. Explained in a way even I can understand.
So after explaining fractional reserve banking and why it is not the reason for inflation (the central bank of central banking is), this guy argues for a commodity-backed free banking system (of course as a commodity I myself am thinking: "bitcoin", here).
It has been argued in this thread that with bitcoin banking would be obsolete. I'm not so sure. Deposit/Loan banking is still different from "people pooling money to invest", because with banking, the people (savers) do not usually concern themselves with selecting how the money is invested (who it is loaned out to) nor do they carry the default risk directly.
As I understand it in a free banking system the banks would control each other to not overdue it with the reserves they keep and the riskyness of loans they make.
So banks make saving possible in a relatively risk-free and easy way. So they perform a valuable function.
Another thought: Thinking about how supposedly nationstates use their currency to "regulate" their economy (they have a weaker economy so they need to have a weaker currency) and seeing the Euro fail (not sure wether it's because differences in fiscal policy or because all fiat currencies are failing) there is a question bugging me:
would a single-currency world economy work?