I use cellular....o.k. I admitted it. Don't hate me because I'm cellular. That said...I don't dial while driving and it's lever left on so I will be tempted to answer it while driving. I have a pager, most folks don't even know the cell number. I can be paged anytime and respond by cell when it's safe.
The other side of this coin is good for the bicyclist though, I think. It is a comfort to me to have my cell phone (turned off) stuffed in the under seat bag of my bike while out on long rides. If an emergency or mechanical malfunction happens at the farthest point from home I can call some body to come get me.