If you’re the type that really craves extra screen real estate with a minimum of hassle, you probably dig these USB monitors we’re seeing these days. But if you also happen to be hard up for cash, the Luma Labs UD7 may be what you’re looking for. Well, maybe if you have low expectations. The UD7 is a mere 1.5 inches across. The practical upshot of its small size is the similarly small price of $30.