Garmin Nuvi 3790T is one of the lightest and slimmest portable GPS systems ever. With 4.8-inch width and 2.9-inch height, the Garmin GPS device is looking fantastic. Voice Command, Bluetooth and free traffic data make the device smart. But its glossy screen creates glare when it meets with the direct sunlight. One another shortfall of the device is that you can’t access data placing it in your hand. The 4.3-inch GPS navigator comes with a hefty price of about $350.