Like a slinky, but with more electricity

What rolls down stairs alone or in pairs, rolls over your neighbor's dog? What's great for a snack and fits on your back? It's, well ... it's not log at all. BUT it is more foldable, bendable, and cutable than a kitten...it's a new battery! Just think of all the oncoming advances in consumer electronics thanks to a smaller, more adaptable power source:

-watches that affix to your wrist like a postage stamp
-sunglasses with a HUD display
-MP3 players embedded in your skin so that you can have your own background music all of the time

Oh, but the itching, so much itching ....