I'll admit: If I'm on the ferry in to work, and someone's tapping away at an iOS device, I'm not above sneaking a peek. "Hey, that guy's pretty good at Threes," I might say to myself. Or "I wonder what that email's about." And on occasion, "I don't think public transit is an appropriate venue to be watching that movie."

What my fellow passengers should probably do is avail themselves of an accessory that might shield their devices from the wandering eyes of snoops. I spotted a pair of privacy protectors while waking the floor this week at Macworld/iWorld--and I didn't even have to glance around surreptitiously to spy them.

Privacy is really not the main goal of the Hoodini, the latest $37 iPad sunshade from Hoodivision. After all, it's hard to keep things on the QT when you're blocking everyone else's view of your iPad with a hood in colors like crimson red, sapphire blue, or camouflage. (Then again, a camouflage hood over your iPad pretty much tells the world you'd prefer not to be seen if only your surroundings would cooperate.) But make no mistake, attach a Hoodini to your tablet using magnets and nanogrip technology, and no one around you will be able to get a glance at your screen without your express permission.

The Hoodini for the iPad air and the mini and the Hoodi for earlier iPads block out something more unforgiving than other people's eyeballs: the glare of the sun. The Hoodini casts a nice bit of shade, allowing you to actually see your iPad screen in broad daylight. Hoodivision says its shades can keep your iPad up to 20 degrees cooler than they would be in the unforgiving sun, reducing the risk of tablet heat stroke.

But that won't help you if you've got an iPhone and not an iPad, will it? No worries: A few rows away on the Moscone Center show floor, zNitro was showing off its latest screen protector, the Nitro Glass Privacy. It's a screen protector with an adhesive backing that you peel and stick on your iPhone 5 (or assorted Android phones from Samsung if that's the choice you've made with your life). But it's also opaque, so the only way to see what's on the screen is to look at it head on--no sideways glances will be tolerated here.

You get a little more than privacy with zNitro's new $49 screen protector; you also get a measure of durability. zNitro reps were busy throughout this week's trade show attacking their screen protectors with a stapler. You'll be happy to know the Nitro Glass-equipped phones showed no ill effect from the assault.

The Nitro Glass Privacy ships in April.