When I'm dining with someone, and I realize that I'm being rude and looking at my phone, I will put the phone on the table -- face down -- as a sign that I am consciously putting the phone away. The other people can see that I'm not able to discretely look at my phone, and that it doesn't rule me. If the phone was face up, I can see how people would think my attention is being diverted to whatever incoming text/msg is on my phone.