Passwords and smart cards are designed to protect valuable data, but they're useless if you can't remember your password or left your smart card at home on the nightstand.

Biometrics technology, the use of fingerprint imaging, retinal scans, or voice maps to authenticate users, is gaining wider use in the data-security industry. Three new biometrics products, designed to secure desktop PCs and control employee access, were released this week at the Comdex trade show in Las Vegas.

- Sense Technologies Inc., a biometrics company that manufacturers time and attendance systems and employee tracking systems based on fingerprint imaging, displayed its latest product, Checkprint A/C, which controls access to buildings, offices, and other secure areas with fingerprint authentication. Checkprint A/C will be available in late December.

- Ethentica Inc. introduced its Ethenticator USB 2500 Touch Verification product for PCs. The device allows access to local and remote networks based on a fingerprint. It's compatible with Windows 98, ME, and NT 4.0, and it's available now for $99.

- Siemens Inc. displayed a new biometrics mouse that authenticates users' identities via fingerprints. The Siemens ID Mouse is embedded with a next-generation fingertip sensor that scans a picture of the user's fingerprint before granting access to secure computer files. This product is available for about $150.

Biometrics is a more accurate method of data security than passwords and smart cards, Gartner Group VP Richard Hunter says. "Ultimately it will be the most widely used," he says. Gartner Group expects widespread adoption of biometrics technology by corporations and consumers by 2005, but the majority of companies today are na?ve about how vulnerable their assets are, Hunter says. And while biometrics technology will reduce security problems at corporations, he says, even that can't eliminate the problem.