|It's been said that cash is king, but lately it's been getting a little competition from a currency you can't see. It's called Bitcoin. Despite its name, you can't hold it in your hand. It's a digital form of money that only exists in cyberspace, sent globally from one computer to another. You can buy Bitcoin online. The currency is then stored in a digital wallet on your computer. There are no rules or regulations. It's not connected to any bank or government, which suits Bitcoin's anti-establishment advocates just fine. Alexis Christoforous reports.