A long time ago Jim said to Bob that he was going walkabout for a month, and would he look after his stuff?  Bob said fine; stick it in my spare cave.  Then Pete and Gary said that they wanted to go walkabout as well, and would Bob look after their stuff as well?  Bob said sure.  But then Gary said "how are you going to tell my stuff from Pete's and Jim's?  So Bob came up with an idea, and gave them all pieces of paper with different numbers on so that when they came back and gave him their bit of paper, he would know which stuff to give them.  Eventually, Bob started taking a percentage of their goods in return for looking after them.  Pete, Jim and Gary in time got hacked off with always going home again just to check that their possessions were still OK, so they swapped their bits of paper for stuff where they were, and the new owners of the bits of paper went to Bob's cave multiplex and redeemed the goods for themselves.  This is the origin of money.  God, I hate banks.  When you've digested that, go here.  And here, because this is probably the best yet for sheer style.