Let's assume you're sitting in a figurative orchestra, your figurative clarinet resting upon your figurative lap. The figurative piece that the group is rehearsing involves lots of everyone else and little of Mr. or Ms. You. You are bored!
In this situation I tend to watch the crazy conductor's hair. She keeps it like the curling irons never left and it bounces around and gets caught in her mouth sometimes. When the novelty of that wears off I turn to my clarinet brethren, who return sullen stares because they are the most boring people in the universe. After drawing little things eating the last stanza on every line, I sit back and think about what I'll do when I get home, checking the clock to see if it's moved every thirty or so seconds.
How do you amuse yourself in situations where there is practically nothing to do?