C.H.I.M.P. (monitor mirror)
"When you are playing Quake on the local LAN against the support desk staff you need all the help you can get. C.H.I.M.P is an early warning system that will clue you in on when to Alt-Tab back to your spreadsheet when your boss suddenly appears. How does it work? You just look at it and it magically (with its invincible powers) produces an image of what is behind you. Just like a good C.H.I.M.P. should..."
Don't want your boss to catch you spending all your time online looking for recommendations to make so you can win that ThisNext contest? This handy convex mirror will alert you when someone is in the vicinity of your back so you can ALT+TAB.