ThinkLink's FaceCash mobile payment system has debuted several apps (for BlackBerry, iPhone, and Android devices) which allow you to pay for things merely by scanning your phone -- and showing off the attached photo to confirm it is, in fact, your own money that you're spending. You sign up, link your FaceCash account to your personal checking and savings account, and you're good to go with participating merchants. The apps can also store credit card numbers and banking information (perfect for when you lose your phone during a night of heavy partying), making it easier to leave your wallet o