Unless it's in my car and I can't use my smartphone. Another exception is when I am with people and it is socially unacceptable for me to focus on my phone. If we have nothing interesting to talk about, the wait is as painful as ever, perhaps even worse if I am jonesing for my phone.
Standing up a long time can cause physical pain, so that part doesn't go away even if I have a phone.
Also I wonder if smartphones have decreased impulse buys of candy and that other stuff in supermarket lines.