I've been wondering about this for a long time...
Whenever we're traveling state to state (usually in an RV lately), Jim and I are always intrigued to see how different states do things. For example, motorcycle helmet laws, laws regarding cell phone usage while driving, etc.
I finally found the answer to cellphone use while driving...
Turns out, over 30 states have laws regarding cell phone usage while driving.
Thanks to the Consumer Electronics Association, there is now a website that tracks the various cell phone laws by state.
Check it out...
Digital Driver Road Rules
It's simple... All you have to do is hover over a particular state to view the laws in a flash!
More articles like this here:

using a cell phone while driving is against the law over here in the u.k but you are allowed to use a bluetooth divice it has cut down on a lot of road accidents if you are caught using a cell phone by a police officer it gets you an instant fine and points on your lincence if you are caught a second time it could mean you losing your lincence for a year.