Every so often you find a bank of information out on the web and a really creative, knowledgeable person who shares their work openly for the benefit of others and ultimately our students. I recently ran across a resource that Eric Curts from North Canton County Schools created to support teachers in learning how to use Google Presentations to build Comic Strips.
He has a nice example of a strip that teaches osmosis here.
His learning page was created for a presentation he must have done and can be found here. His tutorial presentation has a lot of great ideas and suggestions and can be found here.
He does a fantastic job at explaining images, backgrounds and the settings within Presentations. I think this would be a great idea to model out to kids and perhaps allow kids to work to emulate as a way of learning how to use Presentations. I find kids are much more creative than I and would love to see what they come up with. If you do decide to tray this out, let me know as I would love to help in the process!