I agree with many. This problem has always existed, even in the days of the OHP - remember that thing? We have good tools, let's learn to use them well. I also agree with Toni with respect to keeping the session useful and engaging. A useful book on this is "The winging it logic system" by Keith Spicer. It is about engaging mentally with the audience - you can use PowerPoint with it, but it is designed to work without visual aids. I have used it to make a multi-million dollar proposal that was accepted.