Widely used in Hong Kong, the Octopus card is used for purchases on public
transport, in convenience stores, fast food restaurants and other places where
purchases can be made. In addition it's also used for office and residential
premises access control. Each Octopus card looks like a basic credit card but
has a built-in microchip containing an "electronic purse" and other applications
that records transaction details. To use the card, owners simply wave the card
over a reader and the information or financial transaction is completed
automatically.