I have just run across a website by Garr Reynolds that you really must visit. Garr has a website and blog (Presentation Zen) that deals with issues related to creating and giving presentations using PowerPoint (and Keynote if you are a MAC person). His information goes far beyond the basics of how to set up a good slide (although that is included). His information is about visual communication using these tool. He has posted an article on his website entitled, "Top Ten Slide Tips" that should be a MUST READ for everyone using these tools. If you will simply follow his suggestions your PowerPoint presentations will improve and be far more effective.
Garr makes a very strong point on his website that should be a reminder to everyone making these types of presentations:
"Your presentation is for the benefit of the audience. But boring an audience with bullet point after bullet point is of little benefit to them. Which brings us to the issue of text. The best slides may have no text at all. This may sound insane given the dependency of text slides today, but the best PowerPoint slides will be virtually meaningless with out the narration (that is you). Remember, the slides are meant to support the narration of the speaker, not make the speaker superfluous." - Garr Reynolds
Let that sink in for a minute - he slides are there to SUPPORT what you are saying! Without the benefit of what your narration and speaking, the information on the slide will probably not make sense to anyone.
Visit his website and blog....take his suggestions seriously and your sermon and class presentations will definitely improve, your audience will learn more, and maybe, just maybe they may stay awake more!