Has anyone ever had to speak in front of a large group of people?

I have a morbid fear of this, and it's something that I want to overcome. I've just started a new job, and within our project we have a quarterly seminar where different people get up and talk a bit about the stuff that they've been working on. It's a good idea really, because there's so much happening elsewhere that you get an appreciation of the things that other people are involved in.

Anyway, I've got a fairly senior role within my team, and the last quarterly seminar was presented on behalf of our team by one of the junior engineers (the week that I started - a couple of weeks ago). So, basically, I know that I'll have to do one at some point, so I've asked to do the next one, which'll be in a couple of months time.

So I've got 2 months to try and prepare for this. From what I've read, the only way to conquer one's fear of public speaking, is to just throw yourself in at the deep end. This is what I've done, but so far it hasn't conquered my fear!

Anyone else scared shitless of public speaking?

Any tips..?