Just started doing this a few hours ago. Its definitely not the actualy physical display, because the craziness shows up in a screenshot. (see below). And When I have a window open, or Safari, or iChat, those windows are unaffected, and even cover up the craziness in the background. And on bootup it doesn't show it either. I tried switching my color settings back and forth as well as my resolution or whatever. What the hell? It also has a big square of it next to my pointer too (which doesn't get captured in the screenshot.