That is just plain bullshit, for two reasons:
1. Statistically, if cell phones were that dangerous, accident rates would have skyrocketed over the last 20 years, along with cell phone usage.
2. Practically, there is an attention threshold: it takes a certain amount of attention to drive safely. For most people, there is some "computing capacity" head room for distractions before it interferes with safe driving. People who are bad at managing those distractions are going to be bad drivers all around, not just with cell phones. If someone can't handle driving and talking, they shouldn't be driving at all.
3. Eating and driving is bigger distraction - if you're going to ban cell phones, you'd better ban drive-thru windows also.
4. Personally, I've been driving and talking (and eating [not at the same time ;-) ]) accident free since the days of the Motorola brick.
Texting, on the other hand, is another matter, as the distraction level is vastly higher, and is far more likely to cross that threshold.