This is a quick BASH script to take all of the PowerPoint files in the current working directory and "shuffle" them into a sub-directory named "Shuffled". The script has then been (lightly) tweaked to work within an OS X Automator App and wrapped up as an App that is more easily distributable to faculty.
Drag a folder (containing PowerPoint files) on to the Shuffle.app icon. The app will create a subfolder within the dragged folder, containing all of the PowerPoint files in shuffled order.
For example, if the included Arbitrary Files directory were dragged on to the app, one possible outcome might be:
Arbitrary Files
↳ Shuffled
↳ 1. Presentation C.ppt
2. Presentation A.pptx
3. Presentation D.PPT
4. Presentation B.PPTX
text file.txt