Making useless stuff is important. There are a lot of variations of Useless Machines, with the most common being a machine whose only purpose is to switch itself off once switched on.
After a chat about the marquee tag at work this week (I'm sure web people talk about that weird relic at least once a month) I made something useless of my own. Marrying the deprecated marquee tag with a feature of a now obsolete technology, the DVD player screen saver. It's on CodePen, only really works properly on Chrome, and I have yet to see it hit the corner.