This interesting concept will let you know visually when your batteries are low. Designer Mac Funamizu came up with the Hungry Batteries concept that has the batteries physically slim down more as they hold less charge.

Great idea, but it’s cheaper to just include one of those strips that can tell how much juice is left. If our gadgets also shrank, this would be great. No idea what they are made of or how long they would last.

[Yanko]