If you often find yourself fumbling for your keys on your front porch, perhaps you should look into the Shepherd 210 and Shepherd 220 from ArrowVision Technologies. These devices add fingerprint recognition technology to your doorknob. Powered by six AA batteries, both locks feature fingerprint readers that boast a capture time of less than 1 second and a recognition time of less than 0.2 second per fingerprint. They also have a false accept ratio of less than 4/100,000 and a false reject ratio of less than 3/100, a translation tolerance of less than 3 mm, and a rotation tolerance of less than 15°. Both models can be programmed to recognize up to 50 different fingerprints, and their low-battery alerts won't leave you out in the cold. The 210 can be overwritten with a spare key, while the 220 can be overwritten with a password. Their management systems are accessible through an LED display. For extra security, the 210 provides a deadbolt as well. For more information, go to www.arrowvision.us.