I used to, so I joined the Speech team to get over it. Ever since then, I haven't had problems and I even began to really enjoy public speaking. I'm still not great at it (competitively), but I'm good when it comes to your average public speaking (like school presentations and whatnot).

I can't do it. No matter how large or small the audience, whether I'm speaking to friends or peers, etc, I just can't do it.

I start sweating, and i start shaking violently. The thought of it has my hand twitching.

So I use the internet to make speeches instead.

I used to suck at public speeches. In fact, in terms of the shaking I was just like Ben. Would be shaking the entire time and I wasn't even able to hold a piece of paper still enough to read off of it.

I got over it in college, though. I took a public speaking class and loved it. I took all of my assignments and had fun with them. Instead of fearing looking like a fool in front of the class, I planned to look like a fool in front of the class.

My goal for every speech was to make people laugh, whether at me or with me. Of course I was given quite a bit of freedom with the subjects in the public speaking class (greatest achievement speech: being conceived), but I was able to apply the mentality to other classes and assignments. My delivery for almost every speech is like I'm telling a joke to a small group of friends, then I just amplify my voice.

I can't really think of any advice besides try to have fun with it, don't just try to get through it.

For someone who is loud and outspoken like myself, public speaking is my chance to be like that without seeming like a douche. I get to go up and talk about something, be loud and confident, all that stuff. So like Eric says, find something to enjoy in it and embrace it. Not only will you have a bit of fun, but you won't be stressing about trying to get over with it.

Two problems with that:
1) I'm not loud. In fact, I am incredibly quiet. I only talk if I absolutely have to and would rather not talk at all. Most people think I'm shy, I just don't like talking. Which I guess makes me shy. Whatever.
2) There is absolutely no way to make a presentation about Mahmoud Ahmadenijad fun. Seriously. The man claims the Holocaust is a myth. He wishes to wipe Israel off the map. Oppressing his people. Rigging elections. And he is possibly developing nuclear weapons. How the hell do you make a presentation about one of the worst people I have ever researched fun? ><

Find humor in it. The fact that he's such a whack job is fairly humorous. Not saying your speech should be funny, but learn to enjoy the sheer absurdity of this man during your speech. No one is gonna disagree with your opinion of him, so don't act like you have to convince anyone of anything. You can feel confident knowing that when you start talking, people already agree. Just give them a reason to listen. Connect with them.