The E-Money Band can hold up to $600 and runs off of a system called Edy, which is supported by thousands of Japanese stores. Unfortunately, that support is non-existent in America, making this another awesome Japan-only innovation.
Implications - This is the perfect creation for that person you know who can't seem to keep a wallet or purse longer than a month or two. Wearing your debit card on your wrist like a watch ensures that the moment it's missing, you will notice, and rapidly decreases your chances of misplacing it. Safety and style -- I can deal with that.