Cheapism: Best inexpensive GPS units

When you're driving unfamiliar streets or seeking a nearby spot to fill up your tank and your belly, it helps to have that patient, all-knowing GPS voice directing you to "exit to the right," or, if you've ventured off-course, "make a legal U-turn when possible."Increasingly that voice comes from a smartphone, rather than a stand-alone device. With the right app, a windshield or dashboard mount, a...