One of my biggest high-tech pet peeves is "shoulder surfing," the pervasive and unnerving practice of people wandering (or sneaking) up behind you and reading your laptop screen over your shoulder. It's not that I have military secrets I'm typing up (or really, anything much more scandalous than this blog post). It just makes me feel self-conscious and generally too paralyzed to keep working until the person shoves off.

But of course, for many users, shoulder surfing represents a real security and/or privacy risk, whether you're working at the CIA, a medical office, or the human resources department of your company.

As reported by the Baltimore Sun, Maryland's Oculis Labs has a few solutions for this very issue, all designed to thwart electronic eavesdroppers. One is a sophisticated system called Chameleon, which uses a special eye-tracking camera to keep track of exactly where the authorized user is looking. Software scrambles the text on the entire screen -- the effect, captured on video at the above link, is quite disconcerting -- but leaves intact only that area where the authorized user is looking. It looks incredibly complicated, and would probably take some getting used to, but for ultra-high-security environments, it solves the problem succinctly.

A less complex solution is available in PrivateEye, and it takes no special hardware to work, just the software and your computer's webcam. PrivateEye is simpler in operation than Chameleon. It follows your eyes so when you're looking at the screen, everything is normal. When you look away -- say, to greet a visitor who wandered into your office -- the screen immediately blurs. No fumbling to start the screen saver, and no concerns that you're offending your guest by indiscreetly shutting the lid of your laptop, which he would likely take as a sign that you're trying to hide something from him. (And which you are.) Pretty cool -- all you need are your eyes to make it work.

More brutish methods to address this issue also exist, including polarized privacy screens that allow only someone staring head-on at a monitor to see what it displays (everyone else just sees black).

And for the extreme paranoid (and non-fashion conscious), there's also this (unserious) DIY approach. Happy filtering!