I've got a 27" iMac and unlike most desktop monitors, the iMac doesn't have vertical height adjustment. If I sit straight in my chair (I'm 5'11") with my desk at proper height for my keyboard and mouse, my iMac is almost 10 inches too low. I have it sitting on a bunch of textbooks right now but it's not a great look.. what does everyone else do to raise it up for proper ergonomics?