It's a classic, for sure.
I witnessed a diner tipping $1 Sunday night at a Chili's on a party of 3. What was amazing was he personally handed it to the server, as if he was proud of himself. He was smiling as he did it. To her credit, she was gracious about it and thanked him.
Mrs. BamaVol has a tiny appetite. On days when mine matches hers, we will share an appetizer. But I guarantee one or two rounds of drinks will accompany the appetizer and the tip will be in the 20% range.