Stephen Downes wrote up a useful and comprehensive guide for getting the most value from your experience at conferences. Halfway through, he offers a lovely note on nervousness:
One more tip: love your audience. I know that this may sound weird, but it really does work. When you love your audience, when your focus is on how well you can give your gift to them, everything else melts away. Just remember: they are there to hear you (if your a keynote, they actually invited you and paid your way – how could you not love them? How could you have any doubt that they really want to hear what you have to say?
Agreed. Before I go in front of a group, if I remind myself how much I love the work we do and the people we work with, I have a blast. If I focus on performance and the mechanics of public speaking, I'm a wreck.
Also. 1 John 4:18:
There is no fear in love. But perfect love drives out fear.