I have up-turned unused lengths of packing tape, adhesive-side facing up (clear, but previously had brown because that was what I had available). I think that fits the "Bizarre/Weird" criteria of the topic! But I would prefer not to have it. Here's why...
My Vandersteen speakers have a wood frame on the top with stretched fabric over it. Which makes a wonderful bed for a cat. Except I don't want my cat to stretch the fabric out of shape, and to take ownership of my speakers as another scratching post. The up-turned tape acts as a deterrent - when she jumps on top, the tape sticks to the bottom of her paws, which she hates. Don't worry, it doesn't hurt her, she will jump down and spend some minutes shaking the tape off her paw and walk off being very annoyed. It took a long time (years) to train her not to jump on top of them, but I don't trust her enough to remove the tape, so it stays!