Also great for kids of age to carry a house key - Bracelet key, no more putting keys in your pocket. Great for jogging and wearing pocketless pants. Dude I'm 14 and I still lose house keys I need this badly.
Eyesight-Adjusting Screens: This prototype concept is hi-tech; rather than having to wear glasses to see better, it lets the object adjust to your eyesight. This idea by Ryan Jongwoo Choi is called the iFree.