I was working on a slideshow at home and the application I was using didn't have an option to show files in random order. I wrote a protocol that renamed files in a folder using a random number. It's not a perfect protocol but it did the trick for me.

I posted it in the ScienceCloud Protocol Exchange: 
https://exchange.sciencecloud.com/exchange/browse#details:243,280/Assign Random Filenames

Ton