I got tired of being on planes or at conferences where people could read my laptop over my shoulder. For $30 or so I picked up a 3M Privacy Filter for notebook and LCD monitors. Widescreen PF15.4W. It's 8.18 in x 13.09 in. It makes the screen a tad darker than normal, but it's not bad. I don't even notice it anymore. Doesn't work for people directly behind you, but those at any kind of angle can't see anything.