Look up. That credit card right there is a brilliant concept that'll likely cause quite a few headaches in practice. Dynamics, which makes its ends by coming up with new ways to get the general populace into more debt, has just made public its Redemption payment device -- a newfangled card with a few LEDs, selectors and the ability to let users put their earned points toward any given purchase. The idea goes a little something like this: you roll up to the Old Navy checkout counter, remember that you have 4,300 points logged, and decide that you'd like to cash 'em in towards the purchase of your new threads. You tap the "Request Rewards" side of your card, swipe it and watc
