sounds like the same thing that is available for smart phones, iPads and other tablet computers.
Yup, they have products for all three, as well as for a good selection of camera bodies. In addition to being less reflective than the uncovered screen, the one I installed on my iPad seems to be somewhat more smear-resistant.
Of course, if the manufacturers of these products would engineer them so as not to have screens that were overly reflective, too susceptible to scratches and easy to smear, this type of aftermarket product wouldn't be necessary. In particular, I wish camera manufacturers would provide more robust glass covers for their LCDs—at least for their mid-range and higher bodies.