A currency becomes worth something when people begin accepting it for goods and services. This is already the case to a very limited extent with bitcoin.
This also began to happen with QQ coins, in China people began accepting them for goods and services until the government cracked down. And the funny thing is that this was never meant to happen with QQ coins, they were meant simply as a way for QQ to make more money. But once people accepted them they became a form of currency.
Edit: a teaser: an anonymous coin is one which you can withdraw from the bank, but which the bank can't link to you when you spend it.