Remember the classic Seinfeld episode in which George Costanza's overstuffed wallet eventually exploded on the street? A San Fransisco-based start-up named Coin is introducing a device that's designed to keep your wallet a little less cumbersome. Also called Coin, the product features the ability to store your various credit cards and debit cards -- and even gift and loyalty cards -- in one connected device that's the same shape and size as a standard credit card. Coin users simply plug a magnetic strip reader into their smartphone, swipe their various cards, and sync the information through the company's app. Before making a payment, users tap a button on the back of the Coin card to select which account they prefer to pay with, and the Coin card is swiped through like any other charge card. Check out the following video overview to learn more about Coin, available for pre-order now through the company's site.