Disco cables dance when you do

(Credit: Gearfuse)

Just because a cable lights up, that doesn't necessarily mean it's smart. To wit, Evergreen Japan has developed one that "dances to the rhythm of the music you are listening to," Gearfuse says, but doesn't do much of anything else except maybe keep you from getting run over by a car at night. They also require a clunky battery box to provide power, diluting whatever cool factor they manage to muster--which probably isn't a huge loss.