What to do with spare computers?

I haven’t posted recently, but I now have a reason so read through and let me know what you think.
If you didn’t know, I  have recently started working with a liquidator in my work life.  They usually call me in to backup the data of the company they are liquidating.  This time however they asked that I take care of wiping the hard drives of the desktops and laptops.

Therefore, I recently came into posession of around 20 23 Dell desktops.  Two different models, pretty similar configs.  So now that I have these sitting around awaiting their sale on eBay I am stuck with the question of what to do with them.

I thought about setting up a beowolf cluster.  However, I have nothing to run on it so what fun would it be?  So I am now open for suggestions.

Also, I have some other IT equiptment so if you are looking to buy some stuff check what I have for sale on ebay