I doodle during class all the time. You should see my notebooks. I'm in college so no one minds if I doodle during class. Also if I'm on the phone with someone for a long time I tend to doodle while talking to them.
I doodle quite often in the margins of my notebooks. I feel a bit guilty about it, since I'm supposed to be paying attention in class and not off in my own little world, but I do believe that some good does come of it. Some of my favorite drawings have come from me flipping to a blank page in the middle of class.