To set up the system, you "enroll" your finger (or all 10 digits) by touching the scanner four times, which then records an encrypted data template (not a legal print) of your finger on your computer. Later, you can log in simply by touching the scanner. The software lets you protect individual files or your entire system. And you can even create a "password bank" with your own hypersecure biometric-fingerprint log-in code, replacing all of those hard-to-remember passwords.

Protecting your computer and files in your office is one thing, but what about when you're on the road? All of the antihacking and encryption software in the world won't help if someone walks off with your laptop. According to Safeware Inc., a computer-equipment insurer, 319,000 laptops were stolen in the United States last year. If you want to prevent yours from vanishing, take a look at Targus Defcon 1 ($50) , from Targus International.

Targus seems to be the simplest -- and loudest -- theft deterrent for laptops. About the size of a deck of cards, it has a three-digit combination lock with a built-in motion detector and a steel cable that locks to your laptop or briefcase. Once set, if someone tries to purloin your bag, Targus's motion detector sets off a 110-decibel siren that's guaranteed to turn heads -- and to make a thief drop the goods. Cutting the cable also sets off the alarm. A single 9-volt battery keeps the device running for about three months.

One last question, perhaps only for the truly suspicious: Who goes in your office when you're not there? Are coworkers scanning your computer files or rifling your desk for passwords? Remember, just because you're paranoid doesn't mean that they're not out to get you. To find out what's going on when you're out, set up MicroSentinel ($700) , from Security Data Networks Inc.

The device uses a transmitter that connects to your computer and comes with a wireless 2.4-GHz video camera that can monitor your office from up to 100 feet away. You can program the system's software to take snapshots or to record video or audio whenever it detects motion. The system then calls your cell-phone or pager to alert you to the nefarious activity; it can even email you a photo of the interloper.

Security Data Networks also offers a service that you can access on the Internet using any computer, if you want to check up on your office. You can also set the system to upload shots automatically to your own Web site. The system can be connected to four wireless cameras, at $380 a pop. The only drawback: The cameras won't capture images in a darkened room.

Coordinates: U.are.U Deluxe, Digital Persona Inc., www.digitalpersona.com; Targus Defcon 1, Targus International, www.targus.com; MicroSentinel, Security Data Networks Inc., www.microsentinel.com

John R. Quain (jquain@fastcompany.com) , a Fast Company contributing editor, appears often on CBS News and on MSNBC.

Quain's Top 10 Security Tips

1. Be sure never to give out your social-security number, online or off. This information, in the wrong hands, is a license to steal.

2. Use a paper shredder. Don't just toss out those unsolicited credit-card applications; destroy them.

3. Don't use the same password over and over. Think of variations, tough as they may be to remember.

4. Watch your laptop at the airport. Be especially wary of X-ray-security machines; that's where a lot of laptops disappear.

5. Keep your antivirus software up-to-date. Hackers never rest, so you can't either. Every email attachment potentially contains a virus, so scan it before you open it.

6. Use the latest versions and software patches for your email and your browser. New security loopholes are discovered every week.

7. Don't accept cookies. But if you have to, delete them when you're finished surfing.

8. Use a password to log onto your computer. Most operating systems let you set a password. It's a good idea to establish such a password and to change it regularly.

9. Turn off your computer when you're not using it. It's the only sure way to keep hackers out.

10. Never send an email that you wouldn't want your spouse -- or your boss -- to read. I really can't stress that enough.