In an earlier post, I talked about how it's annoying to see someone simply re-read the text in their PowerPoint slides. I also said that trivial rephrasings aren't quite as annoying or insulting, but they do come awfully close. I also suggested that it helps if we keep the PowerPoint text brief, so that we can expand on their meaning as we speak.
It also helps if we use simple animation effects to make the text appear only as needed. It's trivial to learn, and anybody with even an average IQ can make it work.