I have a dirty secret: I am an inveterate reader of other people's screens. It's a compulsion. I've tried to quit. But I can't. They're invariably more fascinating than my own; so if I'm sitting next to you on the plane, I'll be checking out your e-mails, reading your presentations, and tutting at your use of Comic Sans in your documents. As such, I'm not a fan of HP's new Sure View screens—but I certainly understand their justification.

The Sure View option is being offered on the HP EliteBook 1040 and the EliteBook 840; with one press of a button the screens flip from regular wide viewing angle mode into private mode, slashing the off-axis visibility of the devices.

The effect is pretty significant. On-axis visibility drops a little, as the screen gets dimmer, but off-axis visibility drops substantially. It's definitely enough to stop nosy row-mates on your cattle-class flight from being able to read your e-mails, and even the people in the row behind are going to struggle to see what you're working on.

Privacy filters to cut the viewing angle of screens and make them harder to read from the side are nothing new, but these overlay filters are easily lost, damaged, or forgotten about. HP's new Sure View screen offers for the first time direct integration into a standard laptop, meaning that the filter is always with you, ready to be enabled whenever you need to do something that demands some privacy just by pressing F2. Building this into a laptop makes a lot of sense; laptops are often used in places like airports and coffee shops where shoulder surfing and visual eavesdropping are something of an inevitability.

Sure View embeds the filter, which was developed by 3M, into the screen itself. The extra layer makes the screen marginally dimmer in normal use (though it doesn't interfere with touch screens) and quite a bit dimmer in privacy mode. Accordingly, in privacy mode the battery life of the systems will be slightly reduced. The same will tend to be true of separate filters, too, since they also block some of the light.

The biggest drawback is that right now Sure View only works with TN (twisted nematic) style screens. TN screens tend to be reserved for cheaper laptops, since their viewing angles and color accuracy are inferior to the IPS screens found on high-end devices. HP says it's working to bring Sure View technology to IPS screens and is also considering building desktop monitors with the same capability for environments like cubicle farms and banks.