Admit it, you've done it. Peeked at the laptop next to you in a coffee shop to see what someone was doing. We all are a little curious about what others are doing on their laptop, and 3M has developed a product to keep curious eyes at bay.
3M's Computer Security Filters make your laptop screen unreadable except when you are staring at it head on. By simply applying this protective coating, you make it difficult for wandering eyes to wander over to your screen. It comes in a variety of sizes to fit every laptop.
3M touts it also as a screen-protector, as well as being easier on your eyes although not all users agree. One complaint by an Amazon customer claims it makes the screen too dark for the user, and isn't as effective as promised.
Available here for $40-50.