This awesome and easy hack came to me from Instructables member dimovi. Basically, you take a LCD monitor apart and extract its polarized film. The film then goes into a pair of old glasses and voilà, you have a privacy monitor that looks normal with your snazzy new glasses and blank to everyone else.
This would be a great mod for a laptop, to protect your privacy when you are out and about without buying a screen cover. Though, I’d test this out on a few old monitors before I take apart my precious laptop.
I can definitely see the appeal of this for home, especially if you have noisy roommates or child around. At the office you’d definitely have a cool monitor that might make your co-workers jealous, but I’d wager you won’t win any brownie points with your boss.