From my notebook pages of ridiculous inventions and bad ideas, for your amusement. As I fiddled with a pot of conductive paint and thought about murals on the wall with blinky LEDs, I had the horrible idea of painting a toilet seat with conductive paint in such a way so that when you sit on it, your bare butt completes a circuit and lights up something on the wall. That should be enshrined in the bad inventions hall of fame!
Dog skates would take the idea of dog skateboards and wheelchairs a bit further. Basically you would take an old fashioned metal rollerskate and modify it to strap around the body of a small dog. Then, add a spring-powered suspension system between the body and the wheels, so the dog can easily bounce up and down between a walking and a rolling position. The skate could also be locked with a screw device in a wheels-up or wheels-down position to make the dog walk, or to pull it along on a leash like a little (live) pull toy. I don’t have a dog and don’t even like dogs, but thought of this while staring at other people dragging their reluctant chihuahas around San Francisco, and it made me laugh because it’s such a bad idea.