Similar to Coin, SWYP lets you input all your gift cards and credit cards onto one swipe-able card that hooks up to your smartphone.
Using a dynamic magnetic strip, it will morph into whichever card you need—just toggle the buttons on the face. Additionally, it can guess which card you need based on what time of day it is, making it so you don't have to leaf through the list.
Naturally, every bit is encrypted so it's even more secure than using a real credit card. It also only works within six feet of your phone, so it will die without you, keeping your bank account and credit safe.