Biometric systems stand guard The US-Visit program, run by the Department of Homeland Security, aims to track foreigners visiting the United States. Kiosks that scan passports and fingerprints, and issue printed receipts, are now being tested. Credit: Monika Graf/Getty Images Related stories: Biometric systems stand guard Britain is among the countries moving to create "electronic borders." In this photo, Home Secretary Charles Clarke submits to a fingerprint scan to demonstrate the electronic processing of identity cards. Credit: John D. McHugh/AP Related stories: Biometric systems stand guard Fingerprint readers aren't just for border crossings--they're also starting to provide corporate and personal security in everyday tech gear such as keyboards and mice from Microsoft. Credit: Microsoft Related stories: Biometric systems stand guard Shoppers, too, have been getting into the act at four Piggly Wiggly stores in South Carolina, where a fingerprint reader stands in for a debit card machine (seen here during a test run in early 2005). The supermarket chain plans to expand the number of stores that use the system, provided by a company called Pay By Touch. Credit: Pay By Touch Related stories: Biometric systems stand guard The British government has said that iris scans will soon join fingerprinting as a biometric component of immigration checks. Iris scan technology from Germany's Byometric Systems starts out with a black-and-white image of the eye. An algorithm records more than 240 features of the iris and generates a 512-byte reference template that's encoded and stored in a database or on a smart card. Credit: Byometric Systems Related stories: Biometric systems stand guard U.S. Marines in Iraq on the lookout for insurgents are using a combination of biometric technologies to identify Iraqi civilians entering Fallujah. The tracking system uses thumbprints, a photograph of the face and a retinal scan. Credit: UPI Photo/Jonathan C. Knauth/Marines Related stories: