First, for those who (helpfully and politely) correct my grammer around here, here’s a tee shirt I saw today:
I am the Grammarian about whom your mother warned you.
Second, is it rude to look at your smart phone during meetings? I guess so, but a) everybody does it, b) even well-run meetings are, at some point, inefficient, and c) it is a bit rude, I’m sure, but it’s hard not to and can be done without losing the thread of the conversation. I think it’s quite rude to do anything more than check it–i.e., to respond to an email is impolite.
I will say this: if you’re having a meeting about the economy and the budget deficit, and someone goes into a rap about how the markets and going to punish us for our fiscal policy, the bond vigilantes are coming, the end is near, yada-yada…at that point, it is legitimate to check your phone.