As a public speaker, what I love the most are people with cell phones who spend the first 10 minutes of my talk furiously texting or Facebooking. I especially love those who turn their backs to the speaker because they want to do their Facebooking or tweeting while facing their friends in the back row.
I’m not being sarcastic, I really love such folks because they are the perfect gauge of how successful my talk is. If the talk is good, they start dropping their phones like ripe pears within the first few minutes. Sometimes, the phones actually drop to the floor. This is very enjoyable.