September 11 was quickly followed by calls from some lawmakers and business leaders for a more robust national identification system: ID cards that possess sophisticated biometric data, making them harder to forge than today's driver's licenses. Privacy advocates are strongly opposed, arguing that such cards, while enabling the government to track individuals and access personal data, would do little to separate the innocent citizen from the walking security threat. For now, the Bush administration is cool to the idea, but it's not hard to envision the Department of Homeland Security re-examining the concept if further terrorist attacks occur. More than 30 countries, from Italy to Malaysia, have already introduced "smart" ID cards. If you're eventually issued a national card, it will likely incorporate several of the technologies shown here, combined to make the card readable by both high- and low-tech devices.