Here's a nice feature from the sometimes staid world of in-car GPS devices. The latest from Garmin features a wireless backup camera that'll show what's behind you on its 7-inch display. The ruggedized camera plugs into your vehicle's rearview lights for power, switching on when they do, so you can toggle between that image and the standard navigation screen. The Nüvi 2798LMT package runs $400 and includes the standard Garmin features like voice-activated navigation and free traffic reports and maps.