Using your smart phone for directions is a growing trend. "I use my phone, my iPhone." "My phone works better, so I just use that." But like a G-P-S device, you want to be able to easily see the phone's screen. Consumer Reports checked out smart-phone holders -- eleven in all. They cost anywhere from 9 to 25 dollars. Some mount on the dash or windshield. Others mount on vents … in cup holders … and lighter sockets. One even attaches to the sun visor. Probably not the best design. "Being on the sun visor means you have to take your eyes off the road. And the instructions tell you to put it on the passenger side, which is way out of your line of vision." The ones that sit in your cup holder have the same disadvantage. You'll have to look down, taking your eyes off the road. Plus you can't use your cup holder! Consumer Reports also evaluated how easy each one is to use. How well they hold the phone. And to check for stability, the testers made some quick turns to see if the phones stayed in place … The lighter socket mounts tended to be unstable, shaking a bit while you drive. And the ones that mounted on the vent were flimsy. Jim Travers "The ones that we like the best are the ones that attach to either the windshield or the dashboard. They hold the phone securely and they keep it right where you can see it easily." The favorite among Consumer Reports staffers is the 20-dollar Iottie. It holds different phone models in place, is easy to use, and keeps your eyes in front of you. "Head North on Elville Avenue" ."