I'll bet you can... and a lot of folks can probably talk on a cell phone while driving... but listening and paying attention to the other part of the conversation is another matter.

When one drives and converses with the passenger, that passenger also sees the road, and the situations, and can easily pause if attention is needed outside the auto.

However, some folks cannot drive and talk... my sister as an example, has to look right at you... very scary when riding as a passenger and seeing the eyes come off the road too darn often. Ends conversations quickly.

Other folks simply should not do anything but drive... but hard to find them, and tell them otherwise.

I have noticed an interesting phenomenon though... tailgaters. Watch some tailgaters... if the rest of the road is otherwise clear, and someone is tailgating, in in spite of plenty of clearance to go around/change lanes etc.... they are likely on a cell phone. It seems as though they become lost in the conversation and fixate on another vehicle to "do the driving for them."

Have noticed this a number of times... It is not always true, but often.