If the idea of ever losing your Coin sounds horrifying (as it should), here's some good news for you. Coin detects when your phone is near via a low-power Bluetooth signal and notifies you when you're a certain distance away from it. You won't need to be near your Coin for it to work, but you will need your phone and the dongle to add, manage or delete existing cards.
The device will also disable itself "if it's lost," according to a press release, but it isn't clear whether you can do this from the app or if it does so automatically based on distance from your phone. Each Coin has a battery that will last for two years and will not demagnetize if left near other cards or magnets, and like other cards it is shock and water-resistant.
Neither the press release nor video address the many security concerns with Coin, such as the concept of getting merchants to accept a generic credit card without questioning if the cardholder is the original owner of the card. Coin could also be a card thief's dream come true, making it much easier to store the information from stolen cards on one convenient device. [More: 10 Gifts for the Geek Who Has Everything]