I think that the new mandatory hands free use for cellphones while driving law will probably be a good thing. Now, before I get attacked for being a anti-cellphone nutcase, I do own a cellphone, and I do talk on it while I'm driving. So, No I'm not a nutcase, I'm a hypocrite! I honestly think that this could be a good law.
In my travels on my motorcycle about 4000 miles, I was able to learn some very important lessons to keep myself alive.
1. Always expect the other drivers to not see you, and assume that they are trying to run you over.
2. Always look for the person on a cellphone; people on cellphones rarely turn their head to look before changing lanes. They do a really quick mirror check, and then the gun it into the other lane!
3. Know drivers blind spots.
There are a few more, but these are sufficient for this rant.

Sure, many devices take the focus of a driver off the road: phones, gps, radio, tv.. so on, but I would say that in my observation, more than 80% of the drivers that accidentally cut me off while I was riding my motorcycle, were on the phone.
I was cruising up I-25 in the left lane keeping up with the fast lane traffic. (the slow lane is usually more dangerous to a biker because of all the merging) Just after I passed I-70 I noticed a car in my left mirror that was making erratic maneuvers. I kept my eye on the car, and noticed that the driver was in a very animated conversation on a cellphone. She was flailing her arms,

and pounding on the steering wheel... and getting closer.. She was in the lane next to me, and I kept myself out of her blind spots. Suddenly, seconds later, I see her blinker on, and she is changing lanes very slowly. AH! She was trying to change into my lane with me in the way! She had come almost even with me, and her front wheel was even with my rear wheel. I looked at her in horror, knowing that she was going to pin between the wall and her car very soon.. I quickly shifted into a lower gear and gunned the bike, while waving at her with my free hand, Finally our eyes locked and the look of shock and sheer surprise covered her face.
Saved. Whew.
I saw her hang up, and then while I was still on the highway, I saw her with both of her hands on the wheel.
My dad uses the phone all the time in his trips, but here are the differences; he very rarely changes lanes while he is on the phone, he almost always uses a hands free device, and if it is an important conversation where he will have to pay full attention to the caller, he will pull over.
I think that cellphones are a great tool, but once it distracts the driver from their first job (being safe on the road) then this law is warranted. I think that this law could save some lives. Giving up freedom for safety.. huh.. I'll have to think long and hard about this one.