From Managing Humans by Michael Lopp:
Ask Larry to put his computer away. I mean it. If you can’t vivaciously participate in a meeting you were invited to, you should not be there. “Rands Rands Rands … I take notes on my computer.” No, you don’t. You take notes and when I use some proper noun you don’t recognize, you surf Wikipedia. If notes must be taken, designate one person to do it; I want you asking me what the proper noun is … not consulting Wikipedia. A useful meeting is not a speech; it’s a debate. If I’m up there flapping my lips and you disagree or don’t understand, I don’t want you to nod, I want you to yell at me.