 I think it's rude to have any kind of a phone call in public where other people can hear you. What really drives me crazy is sometimes people are doing that in the woods. Nothing will drive me more insane is when I'm out there hiking in the woods, having a peaceful time, and some joker comes walking along with their phone. Yak, yak, yak, yak, yak, blah, blah, blah, blah, blah, blah, blah, blah.