New research suggests that using hands-free cell phone devices while driving may actually add to the overall risk, according to a Wall Street Journal story released this week. A study by the National Highway Traffic Safety Administration found that people spent more time on the distracting task of dialing when they use headsets and voice-activated dialing systems. The new voice-activated dialing method took nearly twice as long as punching the buttons on the phone the old-fashioned way, according to the study. A sizable body of research concludes that headsets and speaker-phones don't improve safety because it's the mental distraction of talking on the phone, not holding it, that causes the danger while driving. And recent research suggests the devices actually could increase risk by encouraging people to spend more time on their cell phones and drive faster while doing so. An estimated 40 percent of all cellular minutes are spent while in the car, the Journal says.