Some people can drive, hold a conversation on the cell phone, change the radio station, look at the nav, and drink their coffee while driving (not all at the same time, but all while on the cell phone). They just can ... it really is just a luck of the draw from the gene pool. Others shouldn't put their fingers near any extra electronics while they are driving because they simply need all their brain power dedicated to the road.
The problem occurs when people don't police themSELVES. Sometimes I can be cruising down the highway in the travel lane contently not passing anyone while talking on the phone. I can also pass people and use my blinker and merge and exit while on the phone. There are some cases, however, involving heavy traffic or complicated turns and traffic lights that require my full attention, so I put the phone down. People need to realize when they need to take their hands off the phone and focus on the road.
I also have found that hands-free doesn't help me at all, except that it gives me a free right hand (that I don't use when driving except to put on the arm rest). Unless the state DMVs decide to require everyone to pass a "Cellular Road Test," the three options are, 1) People hit cars cause they don't have enough self-control to put the phone down, 2) Phones are banned, thus resulting in a huge anti-prohibition outbreak of insolence, or 3) Officers continue to find people that are driving erraticly or without full control of the vehicle and ticket them harshly. Very harshly. Like, three-months cell phone bill harshly.