There is some sort of fundamental physical law that prevents cables from ever being just exactly the length you need them to be. Cables are always, always, just barely too short, or much much too long. Obviously, this annoys scientists just as much as it does the rest of us, so they've come up with a solution: stretchable cables full of liquid metal.
Just imagine how great it would be if you could drop your cellphone and it would bounce rather than break. Or if you could run over your laptop with a tank and it would just blob out and reform itself. This is the sort of thing that's possible with stretchable and flexible electronics, and it's being worked on right now.
Liquid metal is an awesome thing to play with. Mercury, the most common kind, is sort of toxic and will eventually drive you insane, but before that happens, you can make it do some amazing stuff: play music, and it dances.