Gadget keeps your laptop private

So there you are using your laptop computer at some public venue. You may be traveling on a jet, sitting at a local coffee-shop hotspot, at the library doing research, on a bus, wherever.

As you're doing whatever it is that you do at your computer, you suddenly get the feeling that your personal space is somehow being invaded.

You look up and you spot him. And although he probably quickly turned his gaze away, you realize that for some time now, the guy sitting next to you has been reading what's on your screen.

I've had it happen, and it's a feeling that's hard to describe. I rate it somewhere between a mild annoyance and a personal violation, depending on what I had been viewing at that particular moment.

Reading what's being displayed on my computer is where I have to draw the privacy-intrusion line. At any given moment, my screen could have sensitive data about my business, personal finances, passwords, e-mail and dozens of other private items of which I have no desire to share with some nearby stranger.

Fortunately for me and others who need to use their computers in a public place, 3M has come up with a novel solution: the Privacy Filter.

It is a sheet of transparent film that can be easily attached over any notebook computer's screen. It's a removable, thin, rigid-yet-flexible polymer that also protects the computer's screen from scratches and marks.

The idea is fairly simple in that the film acts as a kind of mini-blind, like the kind you see being used on windows.

But instead of physical slats, the Privacy Filter uses microlouvers that yield the same effect via extremely tiny ridges that allow light to pass through only to someone who is observing from directly in front of the screen.

Someone trying to look from any other angle such as from the right or left side of the screen will see only blackness. In fact, it looks like the computer isn't even turned on unless you are looking at it straight on.

Typically, when you use your computer, you're the one sitting directly in front of the screen, so everything looks normal.

In fact, the Privacy Filter takes things a bit further and enhances the image by using 3M's Vikuiti technology to improve screen color contrast and help reduce headaches and eyestrain. The Privacy Filter is a clever, inexpensive solution to an annoying problem.

Check out the 3M Web site (www.3m.com) on how you measure your screen so you can order the proper size Privacy Filter for your particular computer. Depending on the size, the filters range from $40 to $60.

As Wi-Fi venues continue to pop up all over the country, you'll find yourself going online more frequently. These days when you go to a McDonald's to surf, it might not just be for a Filet-O-Fish sandwich.

So while you're online and munching at one of their public tables, your Privacy Filter-equipped notebook may be just the condiment to keep your meal a happy one.