I've seen some people do stupid stuff while--applying makeup, gabbing on the phone, reading maps--but the two that take the cake are the guys who are reading books and the one I saw while living in Georgia, I kid you not, playing an acoustic guitar while he drove.
In truth, when my phone rings I look to see who's calling. If it's a manager/boss/family I pull over somewhere and call them back asap. But I don't talk on phone when driving.