3M recently sent me a sample of their new 3M Mobile Privacy Film, a twelve dollar adhesive screen protector with "microlouver technology" (essentially what looks like a polarization filter). When applied, this layer makes the screen appear dark and fuzzy when not looking directly at the screen. The margin of angle is fairly tight and the filter does what it advertises. Of course, this also means that watching videos on the iPhone can become a challenge due to the exact nature of the viewing angle necessary to watch without blurring the image.
When I showed the applied film to my son, he was unimpressed, proposing if someone wanted to protect their screen data from prying eyes that they could simply shield their screen with their free hand. While that might not be a practical alternative, it does ask the question of the what audience is 3M appealing to. Clearly this is a product for C-Level executives with trade-secret confidentiality and paranoid security specialists who practice what they preach. However, for the majority of iPhone users, the 3M Mobile Privacy Film may be too great a trade-off of convenience for privacy.
For more information on the #M Mobile Privacy Film, visit http://www.shop3m.com/98044048985.html