Im very funny about being on my phone when I check out. My DH will get mad at me because we'll be talking about something and when it's my turn to check out I will say "okay, it's my turn, gotta go". I think it's incredibly rude to be on my phone when I check out. My Dad - who never ever calls me - called me on Saturday as I was in line at the Dollar Store. So that one time I stayed on the phone. BUT I made sure to pay attention to the cashier and I paid with correct change in a timely manner. And I thanked them too.