Impractical – yes. A cool thing you can do in PowerPoint – yes!
Using the Zoom tool, you can create a slide that zooms into itself endlessly – an Inception effect. Here is my single slide presentation. First, I use the Zoom > Insert > Slide Zoom, and then I use the Drag-and-Drop way to make a slide a linked Zoom image (the music is what I hear when I think of an endless Inception loop).
-Troy @ TLC