I love public speaking! (Which is, as I discovered to my chagrin, not the same as Public Speaking, the class. BIGGEST waste of time ever.) I actually just spoke on Shabbos. I used to be really shy, and even now I’m not the most explosively friendly person, but being the oldest of a bunch of siblings who are even shyer than you doesn’t really give you a lot of room to be shy. Since I got over it, I’ve discovered that it’s really fun. I’ve given divrei Torah and speeches at simchos, and I’m in my school debate club.
I don’t feel nervous until I stand up. Then I agree with what Bored said- it’s the nervousness that pushes the words out and makes it flow.