People are forever missing the point on how to do a presentation. PowerPoint just makes matters worse by encouraging presenters to use the screen for THEIR needs (i.e. putting their speaking notes up on the screen) instead of the audiences needs (i.e. to provide visual clues to the structure and meaning of what is presented).
Doc Searls had some good advice on giving presentations back in 1998 that are still mostly relevant (although the suggestions to use hotbot to steal copyrighted images seems a bit out of touch with the times!).