I think teachers go to their weekly meetings not to discuss important things, but to share their new ways of reading students' expressions and movements. Why do they always call on us when we don't know the answer to a question and when we finally do know an answer, we're never called on? Here are some ways to attempt to avoid being called on, some of which I'm sure the smaller half of you have already tried.
ONE) Pretending to write notes.
That moment you hear the teacher ask a question, stop doodling stick figures with swords battling each other, and actually start copying down whatsoever on the overhead projector word. for. word. Try really hard to look absorbed in these notes when, in actuality, you really have no idea what you're copying down.
TWO) Avoiding eye contact with the teacher.
"Maybe if I don't look, s/he won't call on me." This tactic fails the majority of the time, but you can still attempt to succeed from time to time. This way varies from hiding behind your hair (if you have long hair), to resting your head on your hands with your head tilted opposite the teacher. If you're not comfortable still sitting in your seat, you can also get up to sharpen your pencil.
THREE) Staring back at the teacher.
Return the stare back at the teacher with a smirk as if you know the answer. This can go both ways, if the teacher likes you, they'll more than likely call on you. So depending on which class you have, choose your ways wisely.
FOUR) OOPS. I dropped my pencil.
"Accidentally" dropping your pen or pencil so you can take your time looking for it until the teacher calls someone else. Make sure you fling it far from where you sit so you have to get out of your seat to retrieve it.
And finally,
FIVE) Actually leaving the classroom.
This is the last resort. If you really have no idea what is going on in class and you're extremely desperate, pretend you have a phone call or have to use the restroom. Quietly rush out of the room as if you're in a hurry, the teacher won't be able to call on you.
Now, these tactics I have suggested do not always work, if you still get called on, don't say I didn't warn you.