Nancy Duarte published her fourth book: Slidedocs, about how to design visual documents in PowerPoint (or Keynote) that are meant for reading rather than presenting.
She is on to something. Business communication is getting shorter and shorter, and the role of word processors that used to write long boring memos is taken over by presentation design software that is used to create more visual documents.
Slidedocs is a free download (it is actually a PowerPoint file) that talks you through an approach to make these documents better. Most useful might actually be the file itself, that can serve as a template for your next Slidedoc!