At Startup Weekend Eindhoven 2011, I have had a hard time to make the speech. The problem I had was, my idea was already busted with the second presentation thus I needed to come up with an another existing idea of mine. I made myself clear that no condition will stop me to go out there and make the pitch. Great that I did it.

My lizard brain was working hard to stop me, not to do the thing, but I did easily shut it off, even though the physical effects was high.

It is important to note that, doing you homework well before the pitch/presentation/speech is very important. Write you speech, record your own sound and listen very carefully to your tone and keep on doing. You will get better, and don't forget to do it in the real world, not in your safety zone, not to your friends/mom/girlfriend. Deliver it to an audience of 100. You are going to see the difference.

Anyway, here is another great article at HBR about speech http://blogs.hbr.org/pallotta/2011/03/delivering-the-speech-of-your.html

1. Know your goal. When the speech is over, what do you want the audience saying about it and you? What difference do you want to make? Most speakers never ask this of themselves.
2. Memorize your speech. That's right. Memorize every word of it. Deliver it in front of a mirror five times, six times, ten times. Then deliver it while your kid is screaming in the background, to develop the confidence that you can recite it no matter what distraction pops up. Why memorize it? Because nothing will put an audience to sleep faster than someone reading from a prepared text. Because when you memorize it, it stops being about getting the words right and starts being about getting the feeling right. Imagine if Andrea Bocelli didn't memorize the words to the songs in his repertoire. How much room do you think there would be for him to feel them?
3. If you don't want to knock it out of the park, don't follow rule 2.
4. Practice the transitions. What will get you from one point to the next? Is it "if," or "when," or "then I." Know and memorize the precise construction of each transitional sentence. It's in uncertainty about transitions from one point to the next that people lose their grace in public and start saying "aaahhhh."
5. Don't fear silence. You want to silence a room? Don't talk. Be silent and look at the audience. Five seconds. Seven seconds. Just taking them in. Connecting with them. But never do it for effect. Do it to get intimate with your audience. It silences a room like you wouldn't believe. Why? Because it's not normal. Audiences are used to speakers filling every nanosecond with the sound of their own voice, leaving zero time for reflection. Audiences are used to being avoided, not appreciated. When they come upon someone who can command their own silence, they understand, "This person is serious."
6. Never, ever, ever use PowerPoint as your speech notes. The slides are for your audience, not for you. The moment they see you rattling through a list of bullets that you should have had the courtesy to memorize, they put you in a category with every other boring presenter they've ever seen and you've lost them.
7. Give something of yourself. Don't be afraid to feel something in front of an audience. Don't be afraid to say something that will make you feel something, and that will make the audience feel something.
8. Be yourself. Don't feel you need to mimic the testosterone level of a motivational speaker. You will look and feel fake. Robert Kennedy never tried to copy Martin Luther King's rhetorical skills. RFK was soft-spoken. He owned that. And as a result, was every bit as affecting as King.
9. Don't speak in abstractions. Say what it is that you mean. Plainly. Avoid the lexicon of your own trade. People are sick of it. It doesn't mean anything to them anymore. Speak in human.
10. Feel what's happening in the room and use it to connect your speech to this moment. In this way, if your mike goes out, you can make a joke out of it, rather than it making a nervous wreck, and a joke, out of you.
11. Make eye contact until it scares you. Distribute your eye contact around the room. Not for effect, but because you genuinely want to connect with the people in front of you.
12. Don't miss your own talk. It is a privilege and an honor to be asked to speak. Take the opportunity to commune with other human beings. It's like getting to watch a falling star.
13. Come from a place of love for your audience. That's mastery. When you allow yourself to feel the humanity of your audience, you have succeeded in taking the focus off yourself. There is a universe of difference between this place and a PowerPoint presentation. This is the place from which change is made. From here you can move mountains.