On my computer, I have a folder by the name of
~/public-files/ where I've started to put files in. These files then get synced to my server with rsync, and is made available at files.voxelmanip.se.
The content varies, everything from photos I've taken to screenshots, art or just straight up memes. Just about anything.
It's like when you find some guy's random website, and you realise directory indexes are enabled, so you can sift through their randomly uploaded files. Except, you're welcome with open arms. :)