Droid Razr Maxx is 'longest-lasting' smartphone

Verizon is now offering Motorola's Droid Razr Maxx for $300, with a claimed battery life of up to 21 hours. With a dual-core, 1.2GHz processor, 4.3-inch screen, and an eight megapixel camera, the device is otherwise similar to the previously released Droid Razr, but it's thicker by approximately 2mm....