Coolest innovations around the world

Hong Kong residents can go through their days with just two cards -- a government-issued ID, and the Octopus card.

The Hong Kong ID, which electronically stores personal details and thumbprint data, allows residents to zip through airport customs, access libraries and file health care claims. The government, which began issuing these in 2003 to combat counterfeit IDs and illegal immigration, is working to link more services to the card.

Meanwhile, the Octopus card lets users ride public transit, buy a morning latte, get new jeans, pay phone bills and pick up groceries. Some schools even use Octopus to take attendance, and a growing number of residential and commercial buildings are using it as an access card.

The Octopus system now processes over 13 million transactions daily, valued at over $19 million.

These two smart cards mean lines are short and move quickly in congested areas -- and efficient foot traffic is a necessity in a city as densely populated as Hong Kong. Plus, speedy electronic transactions mean businesses can keep better records and handle less cash.

As one of the first in the world to adopt smart cards for such uses, Hong Kong's system has paved the way for others such as the Oyster card in London, which can be used on public transit. --S.Y.