Just came across this blog of Damian Conway's presentation at OSCON 2005 (Open Source Conference) and he appears to be a highly respected speaker among the geek population. In any case, his tips for presenters are excellent and I wanted to share them. Make sure you click on "the next entry" to read the entire blog.
One of his points is preparation - at least ten to twenty hours of preparation for each hour of presentation. And inject humor...and stories....and pacing. Be entertaining....and passionate. Know visual literacy and know your audience. OK, how tough can all this be? But when you are passionate about something, you do want to present your information to others. Follow his guidelines and you will improve with each presentation you give.