Meet the Walli Smart Wallet: a smart gadget that connects to your smartphone and sends you instant notifications when you are too far from it. It also monitors the card slot you use the most and lets you know when your favorite card has been missing for too long. You can also set a timer for your cards.
Walli has a range of about 100 feet. It is made of leather and runs up to 6 months on a coin cell battery. This smart wallet is currently getting funded on Kickstarter.