For Android only: smart phone app Valet — Automatic Car Locator ($2) remembers where you parked your car, so you can concentrate on more important matters (like where you put your keys). Not only can the app locate your lost auto hidden in a sprawling sea of cars outside a stadium, but you can also use it to set parking meter timers and street sweeping alarms as well. The best part? You don't have to remember to open the app for it to work.
Buy Now: $2