I was working something out in my head the other day, but must've been too lost in that, because my pod-mate said, "That staring contest you were having with your screen? The screen won." "Hey now," protested I in mock-outrage, "I'm only outnumbered two to one: Give me a little credit!"
But he has a point: When you stare at a screen, it stares back. Contemplation is all well and good, but (for me, at least) breakthroughs rarely happen without tweaking, rearranging, experimentally breaking what's on the screen, sometimes even walking away. Anything but continue to stare at a screen that--screensaver and hibernation mode withstanding--doesn't blink.