You can call me paranoid, but I can't sleep unless the files on my PC are guaranteed private, whether from visiting relatives or our house sitter. And I'm just as freaked about leaving traces behind after using someone else's PC. But I'm sawing logs now since I found some surefire ways to keep my data from prying eyes.

I'm fascinated with the idea of a PC that won't work until it has positively identified me. But I'm too cheap for the high-end security stuff. Good thing I found APC's $40 Biometric Password Manager. The device looks like a tiny mouse and connects to my USB port (1.0, 1.1, or 2.0). Once the unit reads and stores my fingerprint, I'm the only one who can log on to the PC. But if, for example, my teenage niece visits, I simply add her and restrict her access to specific applications and files. Each scanned user (up to 20) can enter a password for, say, Web sites or accounting software and, afterward, they merely touch the device to be granted access. All users can also encrypt their files and folders using their fingerprint as the password.

Safe Sharing

My two dogs haven't tried using my PC yet (they prefer their Macs). But most people do have to share their PC with someone, though maybe not someone with four paws and a wet nose. If you regularly share a system with family, friends, and coworkers, you might need a more comprehensive privacy solution: Micro Solutions' LockBox Fingerprint Access Hard Drive. The external device works with USB 1.0, 1.1, and 2.0, and it gives you fingerprint authentication for up to eight users. You can slice the drive into a maximum of seven private partitions; this way you can let some users access every area of the drive and restrict others to specific partitions. The 80GB model costs about $185 online and runs at a speedy 7200 rpm.

Last summer when my wife, Judy, and I vacationed in Alaska, we stayed with friends and at B and Bs. No way was I going to risk domestic tranquility by taking a notebook computer along with me. Instead I used a USB flash drive to protect my privacy while I checked e-mail and browsed the Web on a hotel PC, at a public library, and once at an Internet café. I didn't leave so much as a trace of data on any of the public computers--no e-mail, passwords, or browsing history.

The drive I use is the StealthSurfer, which comes with a special version of Netscape 7 embedded. The device works with Windows XP, 2000, and Me. It's fast because it doesn't need the host PC's browser or e-mail program. Just plug the StealthSurfer into a USB port, log in (depending on your Internet connection, the drive may take 20 seconds to authenticate itself), and you're good to go. I use Netscape to access Yahoo Mail, but it works with any Web-based e-mail program. It's pricey at $100 for 128MB, but that may be money well spent to guard your privacy. And for the super-paranoid, the StealthSurfer provides built-in e-mail encryption.

Privacy to Go

The StealthSurfer's handy to take everywhere because it's tiny. Without a traditional--and unnecessary--plastic case, it's as thin as a dime, under 2 inches long, and three-quarters of an inch wide. I carried the gadget in my wallet throughout Alaska.

If you already have a flash drive, try the $30 P.I. Protector Mobility Suite from Imagine LAN. Unlike the StealthSurfer, the program uses the version of IE, Outlook, or Outlook Express that's already on the host PC. But P.I. Protector tricks the host computer into thinking the apps are on the flash drive--behind the scenes, the utility temporarily changes the location where these applications look for data and settings.

I'd better get my StealthSurfer ready. Judy's set her sights on Costa Rica.

Contributing Editor Steve Bass is the author of PC Annoyances, published by O'Reilly. Contact him at homeoffice@pcworld.com.