1. Bring a gavel to class. Any time you wish to speak, bang the gavel on your desk and say "order in the classroom." When everyone stops to stare at you in shock, you can quickly jump in with your point.
2. Start slow clapping. After the previous person finishes speaking, loudly and slowly start clapping so as to prevent others from talking before you.
3. Pretend to choke. This one requires some acting skills because you need to seem convincing. When the rest of the class is watching you in concern, you can make a quick recovery and start talking.
4. Fall out of your desk. Do not do this quietly, but make a big scene out of it. This will divert attention to you and give you the opportunity to make a statement
5. Form an alliance. Join forces with as many people in the classes you can and develop a secret signal. When you wish to speak, perform the secret signal in order to make the other students in your alliance start humming. This will create general confusion and allow you to speak.
6. Hide in the ceiling before class. Kick your way out and cause panic with your entrance. Everyone else will be stunned into silence.
7. Bribery. I do not want to get too specific on this one. I'm just throwing it out there; when in doubt, bribe.