We play Tetris at work sometimes. Sometimes, we go at it all day long. The trick to not getting caught is not a trip-wire or a series of animal calls down the office hallway, it's a pair of sunglasses. Using the reflection alone, you can spot anyone coming in as long as you're actively paranoid and enjoying the thrill of the chase - just try not to do it too often.

Here are a few ideas NOTCOT found if Oakleys are not your sort of thing. The CHIMP mirrors are available for $10 and the Spoon Sister colorful ones are available for $14.