Perhaps think outside the box and allow your teacher and your audience to discover a new side of you through one of your strong passions. What sorts of things are you interested in?
couldn't agree more.
It doesn't matter what you do (as long as it fits within the criteria of course), as long as you really
want to do it.
Also, try not to go over time. It's quality, not quantity.
And since it's a speech (and NOT an essay), dramatise it a bit. So, pause in the appropriate places, take breathers, alter your voice intonations, and speak S..L..O..W..L..Y. Make sure you write your speech so that you've made time for all this stuff. Studies show that the way you present your speech is actually more important than the speech itself. Naturally, this doesn't mean that the content of your speech should be codswallop. Make sure your speech consists of 2-3 big ideas, which you explain briefly in simple English. Additionally, don't bother with a prop - you don't need it. The teacher is focusing on you; he is marking you. He is not marking how well you know how to use powerpoint/ draw a poster/ hold a visual. People might say that props enhance what you're saying - naaah. You don't need a prop. Why spend time on something you don't need? It's yr 12, you'd want to spend that time studying for another subject.
^ babbled on a bit there, but hopefully some parts are useful.
hmm I'm probably going to face some controversy regarding the prop argument.